1 2 SENDMAIL CONFIGURATION FILES 3 4This document describes the sendmail configuration files. It 5explains how to create a sendmail.cf file for use with sendmail. 6It also describes how to set options for sendmail which are explained 7in the Sendmail Installation and Operation guide (doc/op/op.me). 8 9To get started, you may want to look at tcpproto.mc (for TCP-only 10sites) and clientproto.mc (for clusters of clients using a single 11mail host), or the generic-*.mc files as operating system-specific 12examples. 13 14Table of Content: 15 16INTRODUCTION AND EXAMPLE 17A BRIEF INTRODUCTION TO M4 18FILE LOCATIONS 19OSTYPE 20DOMAINS 21MAILERS 22FEATURES 23HACKS 24SITE CONFIGURATION 25USING UUCP MAILERS 26TWEAKING RULESETS 27MASQUERADING AND RELAYING 28USING LDAP FOR ALIASES, MAPS, AND CLASSES 29LDAP ROUTING 30ANTI-SPAM CONFIGURATION CONTROL 31CONNECTION CONTROL 32STARTTLS 33SMTP AUTHENTICATION 34ADDING NEW MAILERS OR RULESETS 35ADDING NEW MAIL FILTERS 36QUEUE GROUP DEFINITIONS 37NON-SMTP BASED CONFIGURATIONS 38WHO AM I? 39ACCEPTING MAIL FOR MULTIPLE NAMES 40USING MAILERTABLES 41USING USERDB TO MAP FULL NAMES 42MISCELLANEOUS SPECIAL FEATURES 43SECURITY NOTES 44TWEAKING CONFIGURATION OPTIONS 45MESSAGE SUBMISSION PROGRAM 46FORMAT OF FILES AND MAPS 47DIRECTORY LAYOUT 48ADMINISTRATIVE DETAILS 49 50 51+--------------------------+ 52| INTRODUCTION AND EXAMPLE | 53+--------------------------+ 54 55Configuration files are contained in the subdirectory "cf", with a 56suffix ".mc". They must be run through "m4" to produce a ".cf" file. 57You must pre-load "cf.m4": 58 59 m4 ${CFDIR}/m4/cf.m4 config.mc > config.cf 60 61Alternatively, you can simply: 62 63 cd ${CFDIR}/cf 64 ./Build config.cf 65 66where ${CFDIR} is the root of the cf directory and config.mc is the 67name of your configuration file. If you are running a version of M4 68that understands the __file__ builtin (versions of GNU m4 >= 0.75 do 69this, but the versions distributed with 4.4BSD and derivatives do not) 70or the -I flag (ditto), then ${CFDIR} can be in an arbitrary directory. 71For "traditional" versions, ${CFDIR} ***MUST*** be "..", or you MUST 72use -D_CF_DIR_=/path/to/cf/dir/ -- note the trailing slash! For example: 73 74 m4 -D_CF_DIR_=${CFDIR}/ ${CFDIR}/m4/cf.m4 config.mc > config.cf 75 76Let's examine a typical .mc file: 77 78 divert(-1) 79 # 80 # Copyright (c) 1998-2005 Sendmail, Inc. and its suppliers. 81 # All rights reserved. 82 # Copyright (c) 1983 Eric P. Allman. All rights reserved. 83 # Copyright (c) 1988, 1993 84 # The Regents of the University of California. All rights reserved. 85 # 86 # By using this file, you agree to the terms and conditions set 87 # forth in the LICENSE file which can be found at the top level of 88 # the sendmail distribution. 89 # 90 91 # 92 # This is a Berkeley-specific configuration file for HP-UX 9.x. 93 # It applies only to the Computer Science Division at Berkeley, 94 # and should not be used elsewhere. It is provided on the sendmail 95 # distribution as a sample only. To create your own configuration 96 # file, create an appropriate domain file in ../domain, change the 97 # `DOMAIN' macro below to reference that file, and copy the result 98 # to a name of your own choosing. 99 # 100 divert(0) 101 102The divert(-1) will delete the crud in the resulting output file. 103The copyright notice can be replaced by whatever your lawyers require; 104our lawyers require the one that is included in these files. A copyleft 105is a copyright by another name. The divert(0) restores regular output. 106 107 VERSIONID(`<SCCS or RCS version id>') 108 109VERSIONID is a macro that stuffs the version information into the 110resulting file. You could use SCCS, RCS, CVS, something else, or 111omit it completely. This is not the same as the version id included 112in SMTP greeting messages -- this is defined in m4/version.m4. 113 114 OSTYPE(`hpux9')dnl 115 116You must specify an OSTYPE to properly configure things such as the 117pathname of the help and status files, the flags needed for the local 118mailer, and other important things. If you omit it, you will get an 119error when you try to build the configuration. Look at the ostype 120directory for the list of known operating system types. 121 122 DOMAIN(`CS.Berkeley.EDU')dnl 123 124This example is specific to the Computer Science Division at Berkeley. 125You can use "DOMAIN(`generic')" to get a sufficiently bland definition 126that may well work for you, or you can create a customized domain 127definition appropriate for your environment. 128 129 MAILER(`local') 130 MAILER(`smtp') 131 132These describe the mailers used at the default CS site. The local 133mailer is always included automatically. Beware: MAILER declarations 134should only be followed by LOCAL_* sections. The general rules are 135that the order should be: 136 137 VERSIONID 138 OSTYPE 139 DOMAIN 140 FEATURE 141 local macro definitions 142 MAILER 143 LOCAL_CONFIG 144 LOCAL_RULE_* 145 LOCAL_RULESETS 146 147There are a few exceptions to this rule. Local macro definitions which 148influence a FEATURE() should be done before that feature. For example, 149a define(`PROCMAIL_MAILER_PATH', ...) should be done before 150FEATURE(`local_procmail'). 151 152******************************************************************* 153*** BE SURE YOU CUSTOMIZE THESE FILES! They have some *** 154*** Berkeley-specific assumptions built in, such as the name *** 155*** of their UUCP-relay. You'll want to create your own *** 156*** domain description, and use that in place of *** 157*** domain/Berkeley.EDU.m4. *** 158******************************************************************* 159 160 161+----------------------------+ 162| A BRIEF INTRODUCTION TO M4 | 163+----------------------------+ 164 165Sendmail uses the M4 macro processor to ``compile'' the configuration 166files. The most important thing to know is that M4 is stream-based, 167that is, it doesn't understand about lines. For this reason, in some 168places you may see the word ``dnl'', which stands for ``delete 169through newline''; essentially, it deletes all characters starting 170at the ``dnl'' up to and including the next newline character. In 171most cases sendmail uses this only to avoid lots of unnecessary 172blank lines in the output. 173 174Other important directives are define(A, B) which defines the macro 175``A'' to have value ``B''. Macros are expanded as they are read, so 176one normally quotes both values to prevent expansion. For example, 177 178 define(`SMART_HOST', `smart.foo.com') 179 180One word of warning: M4 macros are expanded even in lines that appear 181to be comments. For example, if you have 182 183 # See FEATURE(`foo') above 184 185it will not do what you expect, because the FEATURE(`foo') will be 186expanded. This also applies to 187 188 # And then define the $X macro to be the return address 189 190because ``define'' is an M4 keyword. If you want to use them, surround 191them with directed quotes, `like this'. 192 193Since m4 uses single quotes (opening "`" and closing "'") to quote 194arguments, those quotes can't be used in arguments. For example, 195it is not possible to define a rejection message containing a single 196quote. Usually there are simple workarounds by changing those 197messages; in the worst case it might be ok to change the value 198directly in the generated .cf file, which however is not advised. 199 200 201Notice: 202------- 203 204This package requires a post-V7 version of m4; if you are running the 2054.2bsd, SysV.2, or 7th Edition version. SunOS's /usr/5bin/m4 or 206BSD-Net/2's m4 both work. GNU m4 version 1.1 or later also works. 207Unfortunately, the M4 on BSDI 1.0 doesn't work -- you'll have to use a 208Net/2 or GNU version. GNU m4 is available from 209ftp://ftp.gnu.org/pub/gnu/m4/m4-1.4.tar.gz (check for the latest version). 210EXCEPTIONS: DEC's m4 on Digital UNIX 4.x is broken (3.x is fine). Use GNU 211m4 on this platform. 212 213 214+----------------+ 215| FILE LOCATIONS | 216+----------------+ 217 218sendmail 8.9 has introduced a new configuration directory for sendmail 219related files, /etc/mail. The new files available for sendmail 8.9 -- 220the class {R} /etc/mail/relay-domains and the access database 221/etc/mail/access -- take advantage of this new directory. Beginning with 2228.10, all files will use this directory by default (some options may be 223set by OSTYPE() files). This new directory should help to restore 224uniformity to sendmail's file locations. 225 226Below is a table of some of the common changes: 227 228Old filename New filename 229------------ ------------ 230/etc/bitdomain /etc/mail/bitdomain 231/etc/domaintable /etc/mail/domaintable 232/etc/genericstable /etc/mail/genericstable 233/etc/uudomain /etc/mail/uudomain 234/etc/virtusertable /etc/mail/virtusertable 235/etc/userdb /etc/mail/userdb 236 237/etc/aliases /etc/mail/aliases 238/etc/sendmail/aliases /etc/mail/aliases 239/etc/ucbmail/aliases /etc/mail/aliases 240/usr/adm/sendmail/aliases /etc/mail/aliases 241/usr/lib/aliases /etc/mail/aliases 242/usr/lib/mail/aliases /etc/mail/aliases 243/usr/ucblib/aliases /etc/mail/aliases 244 245/etc/sendmail.cw /etc/mail/local-host-names 246/etc/mail/sendmail.cw /etc/mail/local-host-names 247/etc/sendmail/sendmail.cw /etc/mail/local-host-names 248 249/etc/sendmail.ct /etc/mail/trusted-users 250 251/etc/sendmail.oE /etc/mail/error-header 252 253/etc/sendmail.hf /etc/mail/helpfile 254/etc/mail/sendmail.hf /etc/mail/helpfile 255/usr/ucblib/sendmail.hf /etc/mail/helpfile 256/etc/ucbmail/sendmail.hf /etc/mail/helpfile 257/usr/lib/sendmail.hf /etc/mail/helpfile 258/usr/share/lib/sendmail.hf /etc/mail/helpfile 259/usr/share/misc/sendmail.hf /etc/mail/helpfile 260/share/misc/sendmail.hf /etc/mail/helpfile 261 262/etc/service.switch /etc/mail/service.switch 263 264/etc/sendmail.st /etc/mail/statistics 265/etc/mail/sendmail.st /etc/mail/statistics 266/etc/mailer/sendmail.st /etc/mail/statistics 267/etc/sendmail/sendmail.st /etc/mail/statistics 268/usr/lib/sendmail.st /etc/mail/statistics 269/usr/ucblib/sendmail.st /etc/mail/statistics 270 271Note that all of these paths actually use a new m4 macro MAIL_SETTINGS_DIR 272to create the pathnames. The default value of this variable is 273`/etc/mail/'. If you set this macro to a different value, you MUST include 274a trailing slash. 275 276Notice: all filenames used in a .mc (or .cf) file should be absolute 277(starting at the root, i.e., with '/'). Relative filenames most 278likely cause surprises during operations (unless otherwise noted). 279 280 281+--------+ 282| OSTYPE | 283+--------+ 284 285You MUST define an operating system environment, or the configuration 286file build will puke. There are several environments available; look 287at the "ostype" directory for the current list. This macro changes 288things like the location of the alias file and queue directory. Some 289of these files are identical to one another. 290 291It is IMPERATIVE that the OSTYPE occur before any MAILER definitions. 292In general, the OSTYPE macro should go immediately after any version 293information, and MAILER definitions should always go last. 294 295Operating system definitions are usually easy to write. They may define 296the following variables (everything defaults, so an ostype file may be 297empty). Unfortunately, the list of configuration-supported systems is 298not as broad as the list of source-supported systems, since many of 299the source contributors do not include corresponding ostype files. 300 301ALIAS_FILE [/etc/mail/aliases] The location of the text version 302 of the alias file(s). It can be a comma-separated 303 list of names (but be sure you quote values with 304 commas in them -- for example, use 305 define(`ALIAS_FILE', `a,b') 306 to get "a" and "b" both listed as alias files; 307 otherwise the define() primitive only sees "a"). 308HELP_FILE [/etc/mail/helpfile] The name of the file 309 containing information printed in response to 310 the SMTP HELP command. 311QUEUE_DIR [/var/spool/mqueue] The directory containing 312 queue files. To use multiple queues, supply 313 a value ending with an asterisk. For 314 example, /var/spool/mqueue/qd* will use all of the 315 directories or symbolic links to directories 316 beginning with 'qd' in /var/spool/mqueue as queue 317 directories. The names 'qf', 'df', and 'xf' are 318 reserved as specific subdirectories for the 319 corresponding queue file types as explained in 320 doc/op/op.me. See also QUEUE GROUP DEFINITIONS. 321MSP_QUEUE_DIR [/var/spool/clientmqueue] The directory containing 322 queue files for the MSP (Mail Submission Program, 323 see sendmail/SECURITY). 324STATUS_FILE [/etc/mail/statistics] The file containing status 325 information. 326LOCAL_MAILER_PATH [/bin/mail] The program used to deliver local mail. 327LOCAL_MAILER_FLAGS [Prmn9] The flags used by the local mailer. The 328 flags lsDFMAw5:/|@q are always included. 329LOCAL_MAILER_ARGS [mail -d $u] The arguments passed to deliver local 330 mail. 331LOCAL_MAILER_MAX [undefined] If defined, the maximum size of local 332 mail that you are willing to accept. 333LOCAL_MAILER_MAXMSGS [undefined] If defined, the maximum number of 334 messages to deliver in a single connection. Only 335 useful for LMTP local mailers. 336LOCAL_MAILER_CHARSET [undefined] If defined, messages containing 8-bit data 337 that ARRIVE from an address that resolves to the 338 local mailer and which are converted to MIME will be 339 labeled with this character set. 340LOCAL_MAILER_EOL [undefined] If defined, the string to use as the 341 end of line for the local mailer. 342LOCAL_MAILER_DSN_DIAGNOSTIC_CODE 343 [X-Unix] The DSN Diagnostic-Code value for the 344 local mailer. This should be changed with care. 345LOCAL_SHELL_PATH [/bin/sh] The shell used to deliver piped email. 346LOCAL_SHELL_FLAGS [eu9] The flags used by the shell mailer. The 347 flags lsDFM are always included. 348LOCAL_SHELL_ARGS [sh -c $u] The arguments passed to deliver "prog" 349 mail. 350LOCAL_SHELL_DIR [$z:/] The directory search path in which the 351 shell should run. 352LOCAL_MAILER_QGRP [undefined] The queue group for the local mailer. 353USENET_MAILER_PATH [/usr/lib/news/inews] The name of the program 354 used to submit news. 355USENET_MAILER_FLAGS [rsDFMmn] The mailer flags for the usenet mailer. 356USENET_MAILER_ARGS [-m -h -n] The command line arguments for the 357 usenet mailer. NOTE: Some versions of inews 358 (such as those shipped with newer versions of INN) 359 use different flags. Double check the defaults 360 against the inews man page. 361USENET_MAILER_MAX [undefined] The maximum size of messages that will 362 be accepted by the usenet mailer. 363USENET_MAILER_QGRP [undefined] The queue group for the usenet mailer. 364SMTP_MAILER_FLAGS [undefined] Flags added to SMTP mailer. Default 365 flags are `mDFMuX' for all SMTP-based mailers; the 366 "esmtp" mailer adds `a'; "smtp8" adds `8'; and 367 "dsmtp" adds `%'. 368RELAY_MAILER_FLAGS [undefined] Flags added to the relay mailer. Default 369 flags are `mDFMuX' for all SMTP-based mailers; the 370 relay mailer adds `a8'. If this is not defined, 371 then SMTP_MAILER_FLAGS is used. 372SMTP_MAILER_MAX [undefined] The maximum size of messages that will 373 be transported using the smtp, smtp8, esmtp, or dsmtp 374 mailers. 375SMTP_MAILER_MAXMSGS [undefined] If defined, the maximum number of 376 messages to deliver in a single connection for the 377 smtp, smtp8, esmtp, or dsmtp mailers. 378SMTP_MAILER_MAXRCPTS [undefined] If defined, the maximum number of 379 recipients to deliver in a single connection for the 380 smtp, smtp8, esmtp, or dsmtp mailers. 381SMTP_MAILER_ARGS [TCP $h] The arguments passed to the smtp mailer. 382 About the only reason you would want to change this 383 would be to change the default port. 384ESMTP_MAILER_ARGS [TCP $h] The arguments passed to the esmtp mailer. 385SMTP8_MAILER_ARGS [TCP $h] The arguments passed to the smtp8 mailer. 386DSMTP_MAILER_ARGS [TCP $h] The arguments passed to the dsmtp mailer. 387RELAY_MAILER_ARGS [TCP $h] The arguments passed to the relay mailer. 388SMTP_MAILER_QGRP [undefined] The queue group for the smtp mailer. 389ESMTP_MAILER_QGRP [undefined] The queue group for the esmtp mailer. 390SMTP8_MAILER_QGRP [undefined] The queue group for the smtp8 mailer. 391DSMTP_MAILER_QGRP [undefined] The queue group for the dsmtp mailer. 392RELAY_MAILER_QGRP [undefined] The queue group for the relay mailer. 393RELAY_MAILER_MAXMSGS [undefined] If defined, the maximum number of 394 messages to deliver in a single connection for the 395 relay mailer. 396SMTP_MAILER_CHARSET [undefined] If defined, messages containing 8-bit data 397 that ARRIVE from an address that resolves to one of 398 the SMTP mailers and which are converted to MIME will 399 be labeled with this character set. 400SMTP_MAILER_LL [990] The maximum line length for SMTP mailers 401 (except the relay mailer). 402RELAY_MAILER_LL [2040] The maximum line length for the relay mailer. 403UUCP_MAILER_PATH [/usr/bin/uux] The program used to send UUCP mail. 404UUCP_MAILER_FLAGS [undefined] Flags added to UUCP mailer. Default 405 flags are `DFMhuU' (and `m' for uucp-new mailer, 406 minus `U' for uucp-dom mailer). 407UUCP_MAILER_ARGS [uux - -r -z -a$g -gC $h!rmail ($u)] The arguments 408 passed to the UUCP mailer. 409UUCP_MAILER_MAX [100000] The maximum size message accepted for 410 transmission by the UUCP mailers. 411UUCP_MAILER_CHARSET [undefined] If defined, messages containing 8-bit data 412 that ARRIVE from an address that resolves to one of 413 the UUCP mailers and which are converted to MIME will 414 be labeled with this character set. 415UUCP_MAILER_QGRP [undefined] The queue group for the UUCP mailers. 416FAX_MAILER_PATH [/usr/local/lib/fax/mailfax] The program used to 417 submit FAX messages. 418FAX_MAILER_ARGS [mailfax $u $h $f] The arguments passed to the FAX 419 mailer. 420FAX_MAILER_MAX [100000] The maximum size message accepted for 421 transmission by FAX. 422POP_MAILER_PATH [/usr/lib/mh/spop] The pathname of the POP mailer. 423POP_MAILER_FLAGS [Penu] Flags added to POP mailer. Flags lsDFMq 424 are always added. 425POP_MAILER_ARGS [pop $u] The arguments passed to the POP mailer. 426POP_MAILER_QGRP [undefined] The queue group for the pop mailer. 427PROCMAIL_MAILER_PATH [/usr/local/bin/procmail] The path to the procmail 428 program. This is also used by 429 FEATURE(`local_procmail'). 430PROCMAIL_MAILER_FLAGS [SPhnu9] Flags added to Procmail mailer. Flags 431 DFM are always set. This is NOT used by 432 FEATURE(`local_procmail'); tweak LOCAL_MAILER_FLAGS 433 instead. 434PROCMAIL_MAILER_ARGS [procmail -Y -m $h $f $u] The arguments passed to 435 the Procmail mailer. This is NOT used by 436 FEATURE(`local_procmail'); tweak LOCAL_MAILER_ARGS 437 instead. 438PROCMAIL_MAILER_MAX [undefined] If set, the maximum size message that 439 will be accepted by the procmail mailer. 440PROCMAIL_MAILER_QGRP [undefined] The queue group for the procmail mailer. 441MAIL11_MAILER_PATH [/usr/etc/mail11] The path to the mail11 mailer. 442MAIL11_MAILER_FLAGS [nsFx] Flags for the mail11 mailer. 443MAIL11_MAILER_ARGS [mail11 $g $x $h $u] Arguments passed to the mail11 444 mailer. 445MAIL11_MAILER_QGRP [undefined] The queue group for the mail11 mailer. 446PH_MAILER_PATH [/usr/local/etc/phquery] The path to the phquery 447 program. 448PH_MAILER_FLAGS [ehmu] Flags for the phquery mailer. Flags nrDFM 449 are always set. 450PH_MAILER_ARGS [phquery -- $u] -- arguments to the phquery mailer. 451PH_MAILER_QGRP [undefined] The queue group for the ph mailer. 452CYRUS_MAILER_FLAGS [Ah5@/:|] The flags used by the cyrus mailer. The 453 flags lsDFMnPq are always included. 454CYRUS_MAILER_PATH [/usr/cyrus/bin/deliver] The program used to deliver 455 cyrus mail. 456CYRUS_MAILER_ARGS [deliver -e -m $h -- $u] The arguments passed 457 to deliver cyrus mail. 458CYRUS_MAILER_MAX [undefined] If set, the maximum size message that 459 will be accepted by the cyrus mailer. 460CYRUS_MAILER_USER [cyrus:mail] The user and group to become when 461 running the cyrus mailer. 462CYRUS_MAILER_QGRP [undefined] The queue group for the cyrus mailer. 463CYRUS_BB_MAILER_FLAGS [u] The flags used by the cyrusbb mailer. 464 The flags lsDFMnP are always included. 465CYRUS_BB_MAILER_ARGS [deliver -e -m $u] The arguments passed 466 to deliver cyrusbb mail. 467CYRUSV2_MAILER_FLAGS [A@/:|m] The flags used by the cyrusv2 mailer. The 468 flags lsDFMnqXz are always included. 469CYRUSV2_MAILER_MAXMSGS [undefined] If defined, the maximum number of 470 messages to deliver in a single connection for the 471 cyrusv2 mailer. 472CYRUSV2_MAILER_MAXRCPTS [undefined] If defined, the maximum number of 473 recipients to deliver in a single connection for the 474 cyrusv2 mailer. 475CYRUSV2_MAILER_ARGS [FILE /var/imap/socket/lmtp] The arguments passed 476 to the cyrusv2 mailer. This can be used to 477 change the name of the Unix domain socket, or 478 to switch to delivery via TCP (e.g., `TCP $h lmtp') 479CYRUSV2_MAILER_QGRP [undefined] The queue group for the cyrusv2 mailer. 480CYRUSV2_MAILER_CHARSET [undefined] If defined, messages containing 8-bit data 481 that ARRIVE from an address that resolves to one the 482 Cyrus mailer and which are converted to MIME will 483 be labeled with this character set. 484confEBINDIR [/usr/libexec] The directory for executables. 485 Currently used for FEATURE(`local_lmtp') and 486 FEATURE(`smrsh'). 487QPAGE_MAILER_FLAGS [mDFMs] The flags used by the qpage mailer. 488QPAGE_MAILER_PATH [/usr/local/bin/qpage] The program used to deliver 489 qpage mail. 490QPAGE_MAILER_ARGS [qpage -l0 -m -P$u] The arguments passed 491 to deliver qpage mail. 492QPAGE_MAILER_MAX [4096] If set, the maximum size message that 493 will be accepted by the qpage mailer. 494QPAGE_MAILER_QGRP [undefined] The queue group for the qpage mailer. 495LOCAL_PROG_QGRP [undefined] The queue group for the prog mailer. 496 497Note: to tweak Name_MAILER_FLAGS use the macro MODIFY_MAILER_FLAGS: 498MODIFY_MAILER_FLAGS(`Name', `change') where Name is the first part 499of the macro Name_MAILER_FLAGS (note: that means Name is entirely in 500upper case) and change can be: flags that should be used directly 501(thus overriding the default value), or if it starts with `+' (`-') 502then those flags are added to (removed from) the default value. 503Example: 504 505 MODIFY_MAILER_FLAGS(`LOCAL', `+e') 506 507will add the flag `e' to LOCAL_MAILER_FLAGS. Notice: there are 508several smtp mailers all of which are manipulated individually. 509See the section MAILERS for the available mailer names. 510WARNING: The FEATUREs local_lmtp and local_procmail set LOCAL_MAILER_FLAGS 511unconditionally, i.e., without respecting any definitions in an 512OSTYPE setting. 513 514 515+---------+ 516| DOMAINS | 517+---------+ 518 519You will probably want to collect domain-dependent defines into one 520file, referenced by the DOMAIN macro. For example, the Berkeley 521domain file includes definitions for several internal distinguished 522hosts: 523 524UUCP_RELAY The host that will accept UUCP-addressed email. 525 If not defined, all UUCP sites must be directly 526 connected. 527BITNET_RELAY The host that will accept BITNET-addressed email. 528 If not defined, the .BITNET pseudo-domain won't work. 529DECNET_RELAY The host that will accept DECNET-addressed email. 530 If not defined, the .DECNET pseudo-domain and addresses 531 of the form node::user will not work. 532FAX_RELAY The host that will accept mail to the .FAX pseudo-domain. 533 The "fax" mailer overrides this value. 534LOCAL_RELAY The site that will handle unqualified names -- that 535 is, names without an @domain extension. 536 Normally MAIL_HUB is preferred for this function. 537 LOCAL_RELAY is mostly useful in conjunction with 538 FEATURE(`stickyhost') -- see the discussion of 539 stickyhost below. If not set, they are assumed to 540 belong on this machine. This allows you to have a 541 central site to store a company- or department-wide 542 alias database. This only works at small sites, 543 and only with some user agents. 544LUSER_RELAY The site that will handle lusers -- that is, apparently 545 local names that aren't local accounts or aliases. To 546 specify a local user instead of a site, set this to 547 ``local:username''. 548 549Any of these can be either ``mailer:hostname'' (in which case the 550mailer is the internal mailer name, such as ``uucp-new'' and the hostname 551is the name of the host as appropriate for that mailer) or just a 552``hostname'', in which case a default mailer type (usually ``relay'', 553a variant on SMTP) is used. WARNING: if you have a wildcard MX 554record matching your domain, you probably want to define these to 555have a trailing dot so that you won't get the mail diverted back 556to yourself. 557 558The domain file can also be used to define a domain name, if needed 559(using "DD<domain>") and set certain site-wide features. If all hosts 560at your site masquerade behind one email name, you could also use 561MASQUERADE_AS here. 562 563You do not have to define a domain -- in particular, if you are a 564single machine sitting off somewhere, it is probably more work than 565it's worth. This is just a mechanism for combining "domain dependent 566knowledge" into one place. 567 568 569+---------+ 570| MAILERS | 571+---------+ 572 573There are fewer mailers supported in this version than the previous 574version, owing mostly to a simpler world. As a general rule, put the 575MAILER definitions last in your .mc file. 576 577local The local and prog mailers. You will almost always 578 need these; the only exception is if you relay ALL 579 your mail to another site. This mailer is included 580 automatically. 581 582smtp The Simple Mail Transport Protocol mailer. This does 583 not hide hosts behind a gateway or another other 584 such hack; it assumes a world where everyone is 585 running the name server. This file actually defines 586 five mailers: "smtp" for regular (old-style) SMTP to 587 other servers, "esmtp" for extended SMTP to other 588 servers, "smtp8" to do SMTP to other servers without 589 converting 8-bit data to MIME (essentially, this is 590 your statement that you know the other end is 8-bit 591 clean even if it doesn't say so), "dsmtp" to do on 592 demand delivery, and "relay" for transmission to the 593 RELAY_HOST, LUSER_RELAY, or MAIL_HUB. 594 595uucp The UNIX-to-UNIX Copy Program mailer. Actually, this 596 defines two mailers, "uucp-old" (a.k.a. "uucp") and 597 "uucp-new" (a.k.a. "suucp"). The latter is for when you 598 know that the UUCP mailer at the other end can handle 599 multiple recipients in one transfer. If the smtp mailer 600 is included in your configuration, two other mailers 601 ("uucp-dom" and "uucp-uudom") are also defined [warning: you 602 MUST specify MAILER(`smtp') before MAILER(`uucp')]. When you 603 include the uucp mailer, sendmail looks for all names in 604 class {U} and sends them to the uucp-old mailer; all 605 names in class {Y} are sent to uucp-new; and all 606 names in class {Z} are sent to uucp-uudom. Note that 607 this is a function of what version of rmail runs on 608 the receiving end, and hence may be out of your control. 609 See the section below describing UUCP mailers in more 610 detail. 611 612usenet Usenet (network news) delivery. If this is specified, 613 an extra rule is added to ruleset 0 that forwards all 614 local email for users named ``group.usenet'' to the 615 ``inews'' program. Note that this works for all groups, 616 and may be considered a security problem. 617 618fax Facsimile transmission. This is experimental and based 619 on Sam Leffler's HylaFAX software. For more information, 620 see http://www.hylafax.org/. 621 622pop Post Office Protocol. 623 624procmail An interface to procmail (does not come with sendmail). 625 This is designed to be used in mailertables. For example, 626 a common question is "how do I forward all mail for a given 627 domain to a single person?". If you have this mailer 628 defined, you could set up a mailertable reading: 629 630 host.com procmail:/etc/procmailrcs/host.com 631 632 with the file /etc/procmailrcs/host.com reading: 633 634 :0 # forward mail for host.com 635 ! -oi -f $1 person@other.host 636 637 This would arrange for (anything)@host.com to be sent 638 to person@other.host. In a procmail script, $1 is the 639 name of the sender and $2 is the name of the recipient. 640 If you use this with FEATURE(`local_procmail'), the FEATURE 641 should be listed first. 642 643 Of course there are other ways to solve this particular 644 problem, e.g., a catch-all entry in a virtusertable. 645 646mail11 The DECnet mail11 mailer, useful only if you have the mail11 647 program from gatekeeper.dec.com:/pub/DEC/gwtools (and 648 DECnet, of course). This is for Phase IV DECnet support; 649 if you have Phase V at your site you may have additional 650 problems. 651 652phquery The phquery program. This is somewhat counterintuitively 653 referenced as the "ph" mailer internally. It can be used 654 to do CCSO name server lookups. The phquery program, which 655 this mailer uses, is distributed with the ph client. 656 657cyrus The cyrus and cyrusbb mailers. The cyrus mailer delivers to 658 a local cyrus user. this mailer can make use of the 659 "user+detail@local.host" syntax (see 660 FEATURE(`preserve_local_plus_detail')); it will deliver the 661 mail to the user's "detail" mailbox if the mailbox's ACL 662 permits. The cyrusbb mailer delivers to a system-wide 663 cyrus mailbox if the mailbox's ACL permits. The cyrus 664 mailer must be defined after the local mailer. 665 666cyrusv2 The mailer for Cyrus v2.x. The cyrusv2 mailer delivers to 667 local cyrus users via LMTP. This mailer can make use of the 668 "user+detail@local.host" syntax (see 669 FEATURE(`preserve_local_plus_detail')); it will deliver the 670 mail to the user's "detail" mailbox if the mailbox's ACL 671 permits. The cyrusv2 mailer must be defined after the 672 local mailer. 673 674qpage A mailer for QuickPage, a pager interface. See 675 http://www.qpage.org/ for further information. 676 677The local mailer accepts addresses of the form "user+detail", where 678the "+detail" is not used for mailbox matching but is available 679to certain local mail programs (in particular, see 680FEATURE(`local_procmail')). For example, "eric", "eric+sendmail", and 681"eric+sww" all indicate the same user, but additional arguments <null>, 682"sendmail", and "sww" may be provided for use in sorting mail. 683 684 685+----------+ 686| FEATURES | 687+----------+ 688 689Special features can be requested using the "FEATURE" macro. For 690example, the .mc line: 691 692 FEATURE(`use_cw_file') 693 694tells sendmail that you want to have it read an /etc/mail/local-host-names 695file to get values for class {w}. A FEATURE may contain up to 9 696optional parameters -- for example: 697 698 FEATURE(`mailertable', `dbm /usr/lib/mailertable') 699 700The default database map type for the table features can be set with 701 702 define(`DATABASE_MAP_TYPE', `dbm') 703 704which would set it to use ndbm databases. The default is the Berkeley DB 705hash database format. Note that you must still declare a database map type 706if you specify an argument to a FEATURE. DATABASE_MAP_TYPE is only used 707if no argument is given for the FEATURE. It must be specified before any 708feature that uses a map. 709 710Also, features which can take a map definition as an argument can also take 711the special keyword `LDAP'. If that keyword is used, the map will use the 712LDAP definition described in the ``USING LDAP FOR ALIASES, MAPS, AND 713CLASSES'' section below. 714 715Available features are: 716 717use_cw_file Read the file /etc/mail/local-host-names file to get 718 alternate names for this host. This might be used if you 719 were on a host that MXed for a dynamic set of other hosts. 720 If the set is static, just including the line "Cw<name1> 721 <name2> ..." (where the names are fully qualified domain 722 names) is probably superior. The actual filename can be 723 overridden by redefining confCW_FILE. 724 725use_ct_file Read the file /etc/mail/trusted-users file to get the 726 names of users that will be ``trusted'', that is, able to 727 set their envelope from address using -f without generating 728 a warning message. The actual filename can be overridden 729 by redefining confCT_FILE. 730 731redirect Reject all mail addressed to "address.REDIRECT" with 732 a ``551 User has moved; please try <address>'' message. 733 If this is set, you can alias people who have left 734 to their new address with ".REDIRECT" appended. 735 736nouucp Don't route UUCP addresses. This feature takes one 737 parameter: 738 `reject': reject addresses which have "!" in the local 739 part unless it originates from a system 740 that is allowed to relay. 741 `nospecial': don't do anything special with "!". 742 Warnings: 1. See the notice in the anti-spam section. 743 2. don't remove "!" from OperatorChars if `reject' is 744 given as parameter. 745 746nocanonify Don't pass addresses to $[ ... $] for canonification 747 by default, i.e., host/domain names are considered canonical, 748 except for unqualified names, which must not be used in this 749 mode (violation of the standard). It can be changed by 750 setting the DaemonPortOptions modifiers (M=). That is, 751 FEATURE(`nocanonify') will be overridden by setting the 752 'c' flag. Conversely, if FEATURE(`nocanonify') is not used, 753 it can be emulated by setting the 'C' flag 754 (DaemonPortOptions=Modifiers=C). This would generally only 755 be used by sites that only act as mail gateways or which have 756 user agents that do full canonification themselves. You may 757 also want to use 758 "define(`confBIND_OPTS', `-DNSRCH -DEFNAMES')" to turn off 759 the usual resolver options that do a similar thing. 760 761 An exception list for FEATURE(`nocanonify') can be 762 specified with CANONIFY_DOMAIN or CANONIFY_DOMAIN_FILE, 763 i.e., a list of domains which are nevertheless passed to 764 $[ ... $] for canonification. This is useful to turn on 765 canonification for local domains, e.g., use 766 CANONIFY_DOMAIN(`my.domain my') to canonify addresses 767 which end in "my.domain" or "my". 768 Another way to require canonification in the local 769 domain is CANONIFY_DOMAIN(`$=m'). 770 771 A trailing dot is added to addresses with more than 772 one component in it such that other features which 773 expect a trailing dot (e.g., virtusertable) will 774 still work. 775 776 If `canonify_hosts' is specified as parameter, i.e., 777 FEATURE(`nocanonify', `canonify_hosts'), then 778 addresses which have only a hostname, e.g., 779 <user@host>, will be canonified (and hopefully fully 780 qualified), too. 781 782stickyhost This feature is sometimes used with LOCAL_RELAY, 783 although it can be used for a different effect with 784 MAIL_HUB. 785 786 When used without MAIL_HUB, email sent to 787 "user@local.host" are marked as "sticky" -- that 788 is, the local addresses aren't matched against UDB, 789 don't go through ruleset 5, and are not forwarded to 790 the LOCAL_RELAY (if defined). 791 792 With MAIL_HUB, mail addressed to "user@local.host" 793 is forwarded to the mail hub, with the envelope 794 address still remaining "user@local.host". 795 Without stickyhost, the envelope would be changed 796 to "user@mail_hub", in order to protect against 797 mailing loops. 798 799mailertable Include a "mailer table" which can be used to override 800 routing for particular domains (which are not in class {w}, 801 i.e. local host names). The argument of the FEATURE may be 802 the key definition. If none is specified, the definition 803 used is: 804 805 hash /etc/mail/mailertable 806 807 Keys in this database are fully qualified domain names 808 or partial domains preceded by a dot -- for example, 809 "vangogh.CS.Berkeley.EDU" or ".CS.Berkeley.EDU". As a 810 special case of the latter, "." matches any domain not 811 covered by other keys. Values must be of the form: 812 mailer:domain 813 where "mailer" is the internal mailer name, and "domain" 814 is where to send the message. These maps are not 815 reflected into the message header. As a special case, 816 the forms: 817 local:user 818 will forward to the indicated user using the local mailer, 819 local: 820 will forward to the original user in the e-mail address 821 using the local mailer, and 822 error:code message 823 error:D.S.N:code message 824 will give an error message with the indicated SMTP reply 825 code and message, where D.S.N is an RFC 1893 compliant 826 error code. 827 828domaintable Include a "domain table" which can be used to provide 829 domain name mapping. Use of this should really be 830 limited to your own domains. It may be useful if you 831 change names (e.g., your company changes names from 832 oldname.com to newname.com). The argument of the 833 FEATURE may be the key definition. If none is specified, 834 the definition used is: 835 836 hash /etc/mail/domaintable 837 838 The key in this table is the domain name; the value is 839 the new (fully qualified) domain. Anything in the 840 domaintable is reflected into headers; that is, this 841 is done in ruleset 3. 842 843bitdomain Look up bitnet hosts in a table to try to turn them into 844 internet addresses. The table can be built using the 845 bitdomain program contributed by John Gardiner Myers. 846 The argument of the FEATURE may be the key definition; if 847 none is specified, the definition used is: 848 849 hash /etc/mail/bitdomain 850 851 Keys are the bitnet hostname; values are the corresponding 852 internet hostname. 853 854uucpdomain Similar feature for UUCP hosts. The default map definition 855 is: 856 857 hash /etc/mail/uudomain 858 859 At the moment there is no automagic tool to build this 860 database. 861 862always_add_domain 863 Include the local host domain even on locally delivered 864 mail. Normally it is not added on unqualified names. 865 However, if you use a shared message store but do not use 866 the same user name space everywhere, you may need the host 867 name on local names. An optional argument specifies 868 another domain to be added than the local. 869 870allmasquerade If masquerading is enabled (using MASQUERADE_AS), this 871 feature will cause recipient addresses to also masquerade 872 as being from the masquerade host. Normally they get 873 the local hostname. Although this may be right for 874 ordinary users, it can break local aliases. For example, 875 if you send to "localalias", the originating sendmail will 876 find that alias and send to all members, but send the 877 message with "To: localalias@masqueradehost". Since that 878 alias likely does not exist, replies will fail. Use this 879 feature ONLY if you can guarantee that the ENTIRE 880 namespace on your masquerade host supersets all the 881 local entries. 882 883limited_masquerade 884 Normally, any hosts listed in class {w} are masqueraded. If 885 this feature is given, only the hosts listed in class {M} (see 886 below: MASQUERADE_DOMAIN) are masqueraded. This is useful 887 if you have several domains with disjoint namespaces hosted 888 on the same machine. 889 890masquerade_entire_domain 891 If masquerading is enabled (using MASQUERADE_AS) and 892 MASQUERADE_DOMAIN (see below) is set, this feature will 893 cause addresses to be rewritten such that the masquerading 894 domains are actually entire domains to be hidden. All 895 hosts within the masquerading domains will be rewritten 896 to the masquerade name (used in MASQUERADE_AS). For example, 897 if you have: 898 899 MASQUERADE_AS(`masq.com') 900 MASQUERADE_DOMAIN(`foo.org') 901 MASQUERADE_DOMAIN(`bar.com') 902 903 then *foo.org and *bar.com are converted to masq.com. Without 904 this feature, only foo.org and bar.com are masqueraded. 905 906 NOTE: only domains within your jurisdiction and 907 current hierarchy should be masqueraded using this. 908 909local_no_masquerade 910 This feature prevents the local mailer from masquerading even 911 if MASQUERADE_AS is used. MASQUERADE_AS will only have effect 912 on addresses of mail going outside the local domain. 913 914masquerade_envelope 915 If masquerading is enabled (using MASQUERADE_AS) or the 916 genericstable is in use, this feature will cause envelope 917 addresses to also masquerade as being from the masquerade 918 host. Normally only the header addresses are masqueraded. 919 920genericstable This feature will cause unqualified addresses (i.e., without 921 a domain) and addresses with a domain listed in class {G} 922 to be looked up in a map and turned into another ("generic") 923 form, which can change both the domain name and the user name. 924 Notice: if you use an MSP (as it is default starting with 925 8.12), the MTA will only receive qualified addresses from the 926 MSP (as required by the RFCs). Hence you need to add your 927 domain to class {G}. This feature is similar to the userdb 928 functionality. The same types of addresses as for 929 masquerading are looked up, i.e., only header sender 930 addresses unless the allmasquerade and/or masquerade_envelope 931 features are given. Qualified addresses must have the domain 932 part in class {G}; entries can be added to this class by the 933 macros GENERICS_DOMAIN or GENERICS_DOMAIN_FILE (analogously 934 to MASQUERADE_DOMAIN and MASQUERADE_DOMAIN_FILE, see below). 935 936 The argument of FEATURE(`genericstable') may be the map 937 definition; the default map definition is: 938 939 hash /etc/mail/genericstable 940 941 The key for this table is either the full address, the domain 942 (with a leading @; the localpart is passed as first argument) 943 or the unqualified username (tried in the order mentioned); 944 the value is the new user address. If the new user address 945 does not include a domain, it will be qualified in the standard 946 manner, i.e., using $j or the masquerade name. Note that the 947 address being looked up must be fully qualified. For local 948 mail, it is necessary to use FEATURE(`always_add_domain') 949 for the addresses to be qualified. 950 The "+detail" of an address is passed as %1, so entries like 951 952 old+*@foo.org new+%1@example.com 953 gen+*@foo.org %1@example.com 954 955 and other forms are possible. 956 957generics_entire_domain 958 If the genericstable is enabled and GENERICS_DOMAIN or 959 GENERICS_DOMAIN_FILE is used, this feature will cause 960 addresses to be searched in the map if their domain 961 parts are subdomains of elements in class {G}. 962 963virtusertable A domain-specific form of aliasing, allowing multiple 964 virtual domains to be hosted on one machine. For example, 965 if the virtuser table contains: 966 967 info@foo.com foo-info 968 info@bar.com bar-info 969 joe@bar.com error:nouser 550 No such user here 970 jax@bar.com error:5.7.0:550 Address invalid 971 @baz.org jane@example.net 972 973 then mail addressed to info@foo.com will be sent to the 974 address foo-info, mail addressed to info@bar.com will be 975 delivered to bar-info, and mail addressed to anyone at baz.org 976 will be sent to jane@example.net, mail to joe@bar.com will 977 be rejected with the specified error message, and mail to 978 jax@bar.com will also have a RFC 1893 compliant error code 979 5.7.0. 980 981 The username from the original address is passed 982 as %1 allowing: 983 984 @foo.org %1@example.com 985 986 meaning someone@foo.org will be sent to someone@example.com. 987 Additionally, if the local part consists of "user+detail" 988 then "detail" is passed as %2 and "+detail" is passed as %3 989 when a match against user+* is attempted, so entries like 990 991 old+*@foo.org new+%2@example.com 992 gen+*@foo.org %2@example.com 993 +*@foo.org %1%3@example.com 994 X++@foo.org Z%3@example.com 995 @bar.org %1%3 996 997 and other forms are possible. Note: to preserve "+detail" 998 for a default case (@domain) %1%3 must be used as RHS. 999 There are two wildcards after "+": "+" matches only a non-empty 1000 detail, "*" matches also empty details, e.g., user+@foo.org 1001 matches +*@foo.org but not ++@foo.org. This can be used 1002 to ensure that the parameters %2 and %3 are not empty. 1003 1004 All the host names on the left hand side (foo.com, bar.com, 1005 and baz.org) must be in class {w} or class {VirtHost}. The 1006 latter can be defined by the macros VIRTUSER_DOMAIN or 1007 VIRTUSER_DOMAIN_FILE (analogously to MASQUERADE_DOMAIN and 1008 MASQUERADE_DOMAIN_FILE, see below). If VIRTUSER_DOMAIN or 1009 VIRTUSER_DOMAIN_FILE is used, then the entries of class 1010 {VirtHost} are added to class {R}, i.e., relaying is allowed 1011 to (and from) those domains. The default map definition is: 1012 1013 hash /etc/mail/virtusertable 1014 1015 A new definition can be specified as the second argument of 1016 the FEATURE macro, such as 1017 1018 FEATURE(`virtusertable', `dbm /etc/mail/virtusers') 1019 1020virtuser_entire_domain 1021 If the virtusertable is enabled and VIRTUSER_DOMAIN or 1022 VIRTUSER_DOMAIN_FILE is used, this feature will cause 1023 addresses to be searched in the map if their domain 1024 parts are subdomains of elements in class {VirtHost}. 1025 1026ldap_routing Implement LDAP-based e-mail recipient routing according to 1027 the Internet Draft draft-lachman-laser-ldap-mail-routing-01. 1028 This provides a method to re-route addresses with a 1029 domain portion in class {LDAPRoute} to either a 1030 different mail host or a different address. Hosts can 1031 be added to this class using LDAPROUTE_DOMAIN and 1032 LDAPROUTE_DOMAIN_FILE (analogously to MASQUERADE_DOMAIN and 1033 MASQUERADE_DOMAIN_FILE, see below). 1034 1035 See the LDAP ROUTING section below for more information. 1036 1037nullclient This is a special case -- it creates a configuration file 1038 containing nothing but support for forwarding all mail to a 1039 central hub via a local SMTP-based network. The argument 1040 is the name of that hub. 1041 1042 The only other feature that should be used in conjunction 1043 with this one is FEATURE(`nocanonify'). No mailers 1044 should be defined. No aliasing or forwarding is done. 1045 1046local_lmtp Use an LMTP capable local mailer. The argument to this 1047 feature is the pathname of an LMTP capable mailer. By 1048 default, mail.local is used. This is expected to be the 1049 mail.local which came with the 8.9 distribution which is 1050 LMTP capable. The path to mail.local is set by the 1051 confEBINDIR m4 variable -- making the default 1052 LOCAL_MAILER_PATH /usr/libexec/mail.local. 1053 If a different LMTP capable mailer is used, its pathname 1054 can be specified as second parameter and the arguments 1055 passed to it (A=) as third parameter, e.g., 1056 1057 FEATURE(`local_lmtp', `/usr/local/bin/lmtp', `lmtp') 1058 1059 WARNING: This feature sets LOCAL_MAILER_FLAGS unconditionally, 1060 i.e., without respecting any definitions in an OSTYPE setting. 1061 1062local_procmail Use procmail or another delivery agent as the local mailer. 1063 The argument to this feature is the pathname of the 1064 delivery agent, which defaults to PROCMAIL_MAILER_PATH. 1065 Note that this does NOT use PROCMAIL_MAILER_FLAGS or 1066 PROCMAIL_MAILER_ARGS for the local mailer; tweak 1067 LOCAL_MAILER_FLAGS and LOCAL_MAILER_ARGS instead, or 1068 specify the appropriate parameters. When procmail is used, 1069 the local mailer can make use of the 1070 "user+indicator@local.host" syntax; normally the +indicator 1071 is just tossed, but by default it is passed as the -a 1072 argument to procmail. 1073 1074 This feature can take up to three arguments: 1075 1076 1. Path to the mailer program 1077 [default: /usr/local/bin/procmail] 1078 2. Argument vector including name of the program 1079 [default: procmail -Y -a $h -d $u] 1080 3. Flags for the mailer [default: SPfhn9] 1081 1082 Empty arguments cause the defaults to be taken. 1083 Note that if you are on a system with a broken 1084 setreuid() call, you may need to add -f $f to the procmail 1085 argument vector to pass the proper sender to procmail. 1086 1087 For example, this allows it to use the maildrop 1088 (http://www.flounder.net/~mrsam/maildrop/) mailer instead 1089 by specifying: 1090 1091 FEATURE(`local_procmail', `/usr/local/bin/maildrop', 1092 `maildrop -d $u') 1093 1094 or scanmails using: 1095 1096 FEATURE(`local_procmail', `/usr/local/bin/scanmails') 1097 1098 WARNING: This feature sets LOCAL_MAILER_FLAGS unconditionally, 1099 i.e., without respecting any definitions in an OSTYPE setting. 1100 1101bestmx_is_local Accept mail as though locally addressed for any host that 1102 lists us as the best possible MX record. This generates 1103 additional DNS traffic, but should be OK for low to 1104 medium traffic hosts. The argument may be a set of 1105 domains, which will limit the feature to only apply to 1106 these domains -- this will reduce unnecessary DNS 1107 traffic. THIS FEATURE IS FUNDAMENTALLY INCOMPATIBLE WITH 1108 WILDCARD MX RECORDS!!! If you have a wildcard MX record 1109 that matches your domain, you cannot use this feature. 1110 1111smrsh Use the SendMail Restricted SHell (smrsh) provided 1112 with the distribution instead of /bin/sh for mailing 1113 to programs. This improves the ability of the local 1114 system administrator to control what gets run via 1115 e-mail. If an argument is provided it is used as the 1116 pathname to smrsh; otherwise, the path defined by 1117 confEBINDIR is used for the smrsh binary -- by default, 1118 /usr/libexec/smrsh is assumed. 1119 1120promiscuous_relay 1121 By default, the sendmail configuration files do not permit 1122 mail relaying (that is, accepting mail from outside your 1123 local host (class {w}) and sending it to another host than 1124 your local host). This option sets your site to allow 1125 mail relaying from any site to any site. In almost all 1126 cases, it is better to control relaying more carefully 1127 with the access map, class {R}, or authentication. Domains 1128 can be added to class {R} by the macros RELAY_DOMAIN or 1129 RELAY_DOMAIN_FILE (analogously to MASQUERADE_DOMAIN and 1130 MASQUERADE_DOMAIN_FILE, see below). 1131 1132relay_entire_domain 1133 This option allows any host in your domain as defined by 1134 class {m} to use your server for relaying. Notice: make 1135 sure that your domain is not just a top level domain, 1136 e.g., com. This can happen if you give your host a name 1137 like example.com instead of host.example.com. 1138 1139relay_hosts_only 1140 By default, names that are listed as RELAY in the access 1141 db and class {R} are treated as domain names, not host names. 1142 For example, if you specify ``foo.com'', then mail to or 1143 from foo.com, abc.foo.com, or a.very.deep.domain.foo.com 1144 will all be accepted for relaying. This feature changes 1145 the behaviour to lookup individual host names only. 1146 1147relay_based_on_MX 1148 Turns on the ability to allow relaying based on the MX 1149 records of the host portion of an incoming recipient; that 1150 is, if an MX record for host foo.com points to your site, 1151 you will accept and relay mail addressed to foo.com. See 1152 description below for more information before using this 1153 feature. Also, see the KNOWNBUGS entry regarding bestmx 1154 map lookups. 1155 1156 FEATURE(`relay_based_on_MX') does not necessarily allow 1157 routing of these messages which you expect to be allowed, 1158 if route address syntax (or %-hack syntax) is used. If 1159 this is a problem, add entries to the access-table or use 1160 FEATURE(`loose_relay_check'). 1161 1162relay_mail_from 1163 Allows relaying if the mail sender is listed as RELAY in 1164 the access map. If an optional argument `domain' (this 1165 is the literal word `domain', not a placeholder) is given, 1166 relaying can be allowed just based on the domain portion 1167 of the sender address. This feature should only be used if 1168 absolutely necessary as the sender address can be easily 1169 forged. Use of this feature requires the "From:" tag to 1170 be used for the key in the access map; see the discussion 1171 of tags and FEATURE(`relay_mail_from') in the section on 1172 anti-spam configuration control. 1173 1174relay_local_from 1175 Allows relaying if the domain portion of the mail sender 1176 is a local host. This should only be used if absolutely 1177 necessary as it opens a window for spammers. Specifically, 1178 they can send mail to your mail server that claims to be 1179 from your domain (either directly or via a routed address), 1180 and you will go ahead and relay it out to arbitrary hosts 1181 on the Internet. 1182 1183accept_unqualified_senders 1184 Normally, MAIL FROM: commands in the SMTP session will be 1185 refused if the connection is a network connection and the 1186 sender address does not include a domain name. If your 1187 setup sends local mail unqualified (i.e., MAIL FROM:<joe>), 1188 you will need to use this feature to accept unqualified 1189 sender addresses. Setting the DaemonPortOptions modifier 1190 'u' overrides the default behavior, i.e., unqualified 1191 addresses are accepted even without this FEATURE. 1192 If this FEATURE is not used, the DaemonPortOptions modifier 1193 'f' can be used to enforce fully qualified addresses. 1194 1195accept_unresolvable_domains 1196 Normally, MAIL FROM: commands in the SMTP session will be 1197 refused if the host part of the argument to MAIL FROM: 1198 cannot be located in the host name service (e.g., an A or 1199 MX record in DNS). If you are inside a firewall that has 1200 only a limited view of the Internet host name space, this 1201 could cause problems. In this case you probably want to 1202 use this feature to accept all domains on input, even if 1203 they are unresolvable. 1204 1205access_db Turns on the access database feature. The access db gives 1206 you the ability to allow or refuse to accept mail from 1207 specified domains for administrative reasons. Moreover, 1208 it can control the behavior of sendmail in various situations. 1209 By default, the access database specification is: 1210 1211 hash -T<TMPF> /etc/mail/access 1212 1213 See the anti-spam configuration control section for further 1214 important information about this feature. Notice: 1215 "-T<TMPF>" is meant literal, do not replace it by anything. 1216 1217blacklist_recipients 1218 Turns on the ability to block incoming mail for certain 1219 recipient usernames, hostnames, or addresses. For 1220 example, you can block incoming mail to user nobody, 1221 host foo.mydomain.com, or guest@bar.mydomain.com. 1222 These specifications are put in the access db as 1223 described in the anti-spam configuration control section 1224 later in this document. 1225 1226delay_checks The rulesets check_mail and check_relay will not be called 1227 when a client connects or issues a MAIL command, respectively. 1228 Instead, those rulesets will be called by the check_rcpt 1229 ruleset; they will be skipped under certain circumstances. 1230 See "Delay all checks" in the anti-spam configuration control 1231 section. Note: this feature is incompatible to the versions 1232 in 8.10 and 8.11. 1233 1234use_client_ptr If this feature is enabled then check_relay will override 1235 its first argument with $&{client_ptr}. This is useful for 1236 rejections based on the unverified hostname of client, 1237 which turns on the same behavior as in earlier sendmail 1238 versions when delay_checks was not in use. See doc/op/op.* 1239 about check_relay, {client_name}, and {client_ptr}. 1240 1241dnsbl Turns on rejection, discarding, or quarantining of hosts 1242 found in a DNS based list. The first argument is used as 1243 the domain in which blocked hosts are listed. A second 1244 argument can be used to change the default error message, 1245 or select one of the operations `discard' and `quarantine'. 1246 Without that second argument, the error message will be 1247 1248 Rejected: IP-ADDRESS listed at SERVER 1249 1250 where IP-ADDRESS and SERVER are replaced by the appropriate 1251 information. By default, temporary lookup failures are 1252 ignored. This behavior can be changed by specifying a 1253 third argument, which must be either `t' or a full error 1254 message. See the anti-spam configuration control section for 1255 an example. The dnsbl feature can be included several times 1256 to query different DNS based rejection lists. See also 1257 enhdnsbl for an enhanced version. 1258 1259 Set the DNSBL_MAP mc option to change the default map 1260 definition from `host'. Set the DNSBL_MAP_OPT mc option 1261 to add additional options to the map specification used. 1262 1263 Some DNS based rejection lists cause failures if asked 1264 for AAAA records. If your sendmail version is compiled 1265 with IPv6 support (NETINET6) and you experience this 1266 problem, add 1267 1268 define(`DNSBL_MAP', `dns -R A') 1269 1270 before the first use of this feature. Alternatively you 1271 can use enhdnsbl instead (see below). Moreover, this 1272 statement can be used to reduce the number of DNS retries, 1273 e.g., 1274 1275 define(`DNSBL_MAP', `dns -R A -r2') 1276 1277 See below (EDNSBL_TO) for an explanation. 1278 1279enhdnsbl Enhanced version of dnsbl (see above). Further arguments 1280 (up to 5) can be used to specify specific return values 1281 from lookups. Temporary lookup failures are ignored unless 1282 a third argument is given, which must be either `t' or a full 1283 error message. By default, any successful lookup will 1284 generate an error. Otherwise the result of the lookup is 1285 compared with the supplied argument(s), and only if a match 1286 occurs an error is generated. For example, 1287 1288 FEATURE(`enhdnsbl', `dnsbl.example.com', `', `t', `127.0.0.2.') 1289 1290 will reject the e-mail if the lookup returns the value 1291 ``127.0.0.2.'', or generate a 451 response if the lookup 1292 temporarily failed. The arguments can contain metasymbols 1293 as they are allowed in the LHS of rules. As the example 1294 shows, the default values are also used if an empty argument, 1295 i.e., `', is specified. This feature requires that sendmail 1296 has been compiled with the flag DNSMAP (see sendmail/README). 1297 1298 Set the EDNSBL_TO mc option to change the DNS retry count 1299 from the default value of 5, this can be very useful when 1300 a DNS server is not responding, which in turn may cause 1301 clients to time out (an entry stating 1302 1303 did not issue MAIL/EXPN/VRFY/ETRN 1304 1305 will be logged). 1306 1307ratecontrol Enable simple ruleset to do connection rate control 1308 checking. This requires entries in access_db of the form 1309 1310 ClientRate:IP.ADD.RE.SS LIMIT 1311 1312 The RHS specifies the maximum number of connections 1313 (an integer number) over the time interval defined 1314 by ConnectionRateWindowSize, where 0 means unlimited. 1315 1316 Take the following example: 1317 1318 ClientRate:10.1.2.3 4 1319 ClientRate:127.0.0.1 0 1320 ClientRate: 10 1321 1322 10.1.2.3 can only make up to 4 connections, the 1323 general limit it 10, and 127.0.0.1 can make an unlimited 1324 number of connections per ConnectionRateWindowSize. 1325 1326 See also CONNECTION CONTROL. 1327 1328conncontrol Enable a simple check of the number of incoming SMTP 1329 connections. This requires entries in access_db of the 1330 form 1331 1332 ClientConn:IP.ADD.RE.SS LIMIT 1333 1334 The RHS specifies the maximum number of open connections 1335 (an integer number). 1336 1337 Take the following example: 1338 1339 ClientConn:10.1.2.3 4 1340 ClientConn:127.0.0.1 0 1341 ClientConn: 10 1342 1343 10.1.2.3 can only have up to 4 open connections, the 1344 general limit it 10, and 127.0.0.1 does not have any 1345 explicit limit. 1346 1347 See also CONNECTION CONTROL. 1348 1349mtamark Experimental support for "Marking Mail Transfer Agents in 1350 Reverse DNS with TXT RRs" (MTAMark), see 1351 draft-stumpf-dns-mtamark-01. Optional arguments are: 1352 1353 1. Error message, default: 1354 1355 550 Rejected: $&{client_addr} not listed as MTA 1356 1357 2. Temporary lookup failures are ignored unless a second 1358 argument is given, which must be either `t' or a full 1359 error message. 1360 1361 3. Lookup prefix, default: _perm._smtp._srv. This should 1362 not be changed unless the draft changes it. 1363 1364 Example: 1365 1366 FEATURE(`mtamark', `', `t') 1367 1368lookupdotdomain Look up also .domain in the access map. This allows to 1369 match only subdomains. It does not work well with 1370 FEATURE(`relay_hosts_only'), because most lookups for 1371 subdomains are suppressed by the latter feature. 1372 1373loose_relay_check 1374 Normally, if % addressing is used for a recipient, e.g. 1375 user%site@othersite, and othersite is in class {R}, the 1376 check_rcpt ruleset will strip @othersite and recheck 1377 user@site for relaying. This feature changes that 1378 behavior. It should not be needed for most installations. 1379 1380authinfo Provide a separate map for client side authentication 1381 information. See SMTP AUTHENTICATION for details. 1382 By default, the authinfo database specification is: 1383 1384 hash /etc/mail/authinfo 1385 1386preserve_luser_host 1387 Preserve the name of the recipient host if LUSER_RELAY is 1388 used. Without this option, the domain part of the 1389 recipient address will be replaced by the host specified as 1390 LUSER_RELAY. This feature only works if the hostname is 1391 passed to the mailer (see mailer triple in op.me). Note 1392 that in the default configuration the local mailer does not 1393 receive the hostname, i.e., the mailer triple has an empty 1394 hostname. 1395 1396preserve_local_plus_detail 1397 Preserve the +detail portion of the address when passing 1398 address to local delivery agent. Disables alias and 1399 .forward +detail stripping (e.g., given user+detail, only 1400 that address will be looked up in the alias file; user+* and 1401 user will not be looked up). Only use if the local 1402 delivery agent in use supports +detail addressing. 1403 1404compat_check Enable ruleset check_compat to look up pairs of addresses 1405 with the Compat: tag -- Compat:sender<@>recipient -- in the 1406 access map. Valid values for the RHS include 1407 DISCARD silently discard recipient 1408 TEMP: return a temporary error 1409 ERROR: return a permanent error 1410 In the last two cases, a 4xy/5xy SMTP reply code should 1411 follow the colon. 1412 1413no_default_msa Don't generate the default MSA daemon, i.e., 1414 DAEMON_OPTIONS(`Port=587,Name=MSA,M=E') 1415 To define a MSA daemon with other parameters, use this 1416 FEATURE and introduce new settings via DAEMON_OPTIONS(). 1417 1418msp Defines config file for Message Submission Program. 1419 See sendmail/SECURITY for details and cf/cf/submit.mc how 1420 to use it. An optional argument can be used to override 1421 the default of `[localhost]' to use as host to send all 1422 e-mails to. Note that MX records will be used if the 1423 specified hostname is not in square brackets (e.g., 1424 [hostname]). If `MSA' is specified as second argument then 1425 port 587 is used to contact the server. Example: 1426 1427 FEATURE(`msp', `', `MSA') 1428 1429 Some more hints about possible changes can be found below 1430 in the section MESSAGE SUBMISSION PROGRAM. 1431 1432 Note: Due to many problems, submit.mc uses 1433 1434 FEATURE(`msp', `[127.0.0.1]') 1435 1436 by default. If you have a machine with IPv6 only, 1437 change it to 1438 1439 FEATURE(`msp', `[IPv6:::1]') 1440 1441 If you want to continue using '[localhost]', (the behavior 1442 up to 8.12.6), use 1443 1444 FEATURE(`msp') 1445 1446queuegroup A simple example how to select a queue group based 1447 on the full e-mail address or the domain of the 1448 recipient. Selection is done via entries in the 1449 access map using the tag QGRP:, for example: 1450 1451 QGRP:example.com main 1452 QGRP:friend@some.org others 1453 QGRP:my.domain local 1454 1455 where "main", "others", and "local" are names of 1456 queue groups. If an argument is specified, it is used 1457 as default queue group. 1458 1459 Note: please read the warning in doc/op/op.me about 1460 queue groups and possible queue manipulations. 1461 1462greet_pause Adds the greet_pause ruleset which enables open proxy 1463 and SMTP slamming protection. The feature can take an 1464 argument specifying the milliseconds to wait: 1465 1466 FEATURE(`greet_pause', `5000') dnl 5 seconds 1467 1468 If FEATURE(`access_db') is enabled, an access database 1469 lookup with the GreetPause tag is done using client 1470 hostname, domain, IP address, or subnet to determine the 1471 pause time: 1472 1473 GreetPause:my.domain 0 1474 GreetPause:example.com 5000 1475 GreetPause:10.1.2 2000 1476 GreetPause:127.0.0.1 0 1477 1478 When using FEATURE(`access_db'), the optional 1479 FEATURE(`greet_pause') argument becomes the default if 1480 nothing is found in the access database. A ruleset called 1481 Local_greet_pause can be used for local modifications, e.g., 1482 1483 LOCAL_RULESETS 1484 SLocal_greet_pause 1485 R$* $: $&{daemon_flags} 1486 R$* a $* $# 0 1487 1488block_bad_helo Reject messages from SMTP clients which provide a HELO/EHLO 1489 argument which is either unqualified, or is one of our own 1490 names (i.e., the server name instead of the client name). 1491 This check is performed at RCPT stage and disabled for the 1492 following cases: 1493 - authenticated sessions, 1494 - connections from IP addresses in class $={R}. 1495 Currently access_db lookups can not be used to 1496 (selectively) disable this test, moreover, 1497 FEATURE(`delay_checks') 1498 is required. 1499 1500require_rdns Reject mail from connecting SMTP clients without proper 1501 rDNS (reverse DNS), functional gethostbyaddr() resolution. 1502 Note: this feature will cause false positives, i.e., there 1503 are legitimate MTAs that do not have proper DNS entries. 1504 Rejecting mails from those MTAs is a local policy decision. 1505 1506 The basic policy is to reject message with a 5xx error if 1507 the IP address fails to resolve. However, if this is a 1508 temporary failure, a 4xx temporary failure is returned. 1509 If the look-up succeeds, but returns an apparently forged 1510 value, this is treated as a temporary failure with a 4xx 1511 error code. 1512 1513 EXCEPTIONS: 1514 1515 Exceptions based on access entries are discussed below. 1516 Any IP address matched using $=R (the "relay-domains" file) 1517 is excepted from the rules. Since we have explicitly 1518 allowed relaying for this host, based on IP address, we 1519 ignore the rDNS failure. 1520 1521 The philosophical assumption here is that most users do 1522 not control their rDNS. They should be able to send mail 1523 through their ISP, whether or not they have valid rDNS. 1524 The class $=R, roughly speaking, contains those IP addresses 1525 and address ranges for which we are the ISP, or are acting 1526 as if the ISP. 1527 1528 If `delay_checks' is in effect (recommended), then any 1529 sender who has authenticated is also excepted from the 1530 restrictions. This happens because the rules produced by 1531 this FEATURE() will not be applied to authenticated senders 1532 (assuming `delay_checks'). 1533 1534 ACCESS MAP ENTRIES: 1535 1536 Entries such as 1537 Connect:1.2.3.4 OK 1538 Connect:1.2 RELAY 1539 will whitelist IP address 1.2.3.4, so that the rDNS 1540 blocking does apply to that IP address 1541 1542 Entries such as 1543 Connect:1.2.3.4 REJECT 1544 will have the effect of forcing a temporary failure for 1545 that address to be treated as a permanent failure. 1546 1547badmx Reject envelope sender addresses (MAIL) whose domain part 1548 resolves to a "bad" MX record. By default these are 1549 MX records which resolve to A records that match the 1550 regular expression: 1551 1552 ^(127\.|10\.|0\.0\.0\.0) 1553 1554 This default regular expression can be overridden by 1555 specifying an argument, e.g., 1556 1557 FEATURE(`badmx', `^127\.0\.0\.1') 1558 1559 Note: this feature requires that the sendmail binary 1560 has been compiled with the options MAP_REGEX and 1561 DNSMAP. 1562 1563+-------+ 1564| HACKS | 1565+-------+ 1566 1567Some things just can't be called features. To make this clear, 1568they go in the hack subdirectory and are referenced using the HACK 1569macro. These will tend to be site-dependent. The release 1570includes the Berkeley-dependent "cssubdomain" hack (that makes 1571sendmail accept local names in either Berkeley.EDU or CS.Berkeley.EDU; 1572this is intended as a short-term aid while moving hosts into 1573subdomains. 1574 1575 1576+--------------------+ 1577| SITE CONFIGURATION | 1578+--------------------+ 1579 1580 ***************************************************** 1581 * This section is really obsolete, and is preserved * 1582 * only for back compatibility. You should plan on * 1583 * using mailertables for new installations. In * 1584 * particular, it doesn't work for the newer forms * 1585 * of UUCP mailers, such as uucp-uudom. * 1586 ***************************************************** 1587 1588Complex sites will need more local configuration information, such as 1589lists of UUCP hosts they speak with directly. This can get a bit more 1590tricky. For an example of a "complex" site, see cf/ucbvax.mc. 1591 1592The SITECONFIG macro allows you to indirectly reference site-dependent 1593configuration information stored in the siteconfig subdirectory. For 1594example, the line 1595 1596 SITECONFIG(`uucp.ucbvax', `ucbvax', `U') 1597 1598reads the file uucp.ucbvax for local connection information. The 1599second parameter is the local name (in this case just "ucbvax" since 1600it is locally connected, and hence a UUCP hostname). The third 1601parameter is the name of both a macro to store the local name (in 1602this case, {U}) and the name of the class (e.g., {U}) in which to store 1603the host information read from the file. Another SITECONFIG line reads 1604 1605 SITECONFIG(`uucp.ucbarpa', `ucbarpa.Berkeley.EDU', `W') 1606 1607This says that the file uucp.ucbarpa contains the list of UUCP sites 1608connected to ucbarpa.Berkeley.EDU. Class {W} will be used to 1609store this list, and $W is defined to be ucbarpa.Berkeley.EDU, that 1610is, the name of the relay to which the hosts listed in uucp.ucbarpa 1611are connected. [The machine ucbarpa is gone now, but this 1612out-of-date configuration file has been left around to demonstrate 1613how you might do this.] 1614 1615Note that the case of SITECONFIG with a third parameter of ``U'' is 1616special; the second parameter is assumed to be the UUCP name of the 1617local site, rather than the name of a remote site, and the UUCP name 1618is entered into class {w} (the list of local hostnames) as $U.UUCP. 1619 1620The siteconfig file (e.g., siteconfig/uucp.ucbvax.m4) contains nothing 1621more than a sequence of SITE macros describing connectivity. For 1622example: 1623 1624 SITE(`cnmat') 1625 SITE(`sgi olympus') 1626 1627The second example demonstrates that you can use two names on the 1628same line; these are usually aliases for the same host (or are at 1629least in the same company). 1630 1631The macro LOCAL_UUCP can be used to add rules into the generated 1632cf file at the place where MAILER(`uucp') inserts its rules. This 1633should only be used if really necessary. 1634 1635+--------------------+ 1636| USING UUCP MAILERS | 1637+--------------------+ 1638 1639It's hard to get UUCP mailers right because of the extremely ad hoc 1640nature of UUCP addressing. These config files are really designed 1641for domain-based addressing, even for UUCP sites. 1642 1643There are four UUCP mailers available. The choice of which one to 1644use is partly a matter of local preferences and what is running at 1645the other end of your UUCP connection. Unlike good protocols that 1646define what will go over the wire, UUCP uses the policy that you 1647should do what is right for the other end; if they change, you have 1648to change. This makes it hard to do the right thing, and discourages 1649people from updating their software. In general, if you can avoid 1650UUCP, please do. 1651 1652The major choice is whether to go for a domainized scheme or a 1653non-domainized scheme. This depends entirely on what the other 1654end will recognize. If at all possible, you should encourage the 1655other end to go to a domain-based system -- non-domainized addresses 1656don't work entirely properly. 1657 1658The four mailers are: 1659 1660 uucp-old (obsolete name: "uucp") 1661 This is the oldest, the worst (but the closest to UUCP) way of 1662 sending messages across UUCP connections. It does bangify 1663 everything and prepends $U (your UUCP name) to the sender's 1664 address (which can already be a bang path itself). It can 1665 only send to one address at a time, so it spends a lot of 1666 time copying duplicates of messages. Avoid this if at all 1667 possible. 1668 1669 uucp-new (obsolete name: "suucp") 1670 The same as above, except that it assumes that in one rmail 1671 command you can specify several recipients. It still has a 1672 lot of other problems. 1673 1674 uucp-dom 1675 This UUCP mailer keeps everything as domain addresses. 1676 Basically, it uses the SMTP mailer rewriting rules. This mailer 1677 is only included if MAILER(`smtp') is specified before 1678 MAILER(`uucp'). 1679 1680 Unfortunately, a lot of UUCP mailer transport agents require 1681 bangified addresses in the envelope, although you can use 1682 domain-based addresses in the message header. (The envelope 1683 shows up as the From_ line on UNIX mail.) So.... 1684 1685 uucp-uudom 1686 This is a cross between uucp-new (for the envelope addresses) 1687 and uucp-dom (for the header addresses). It bangifies the 1688 envelope sender (From_ line in messages) without adding the 1689 local hostname, unless there is no host name on the address 1690 at all (e.g., "wolf") or the host component is a UUCP host name 1691 instead of a domain name ("somehost!wolf" instead of 1692 "some.dom.ain!wolf"). This is also included only if MAILER(`smtp') 1693 is also specified earlier. 1694 1695Examples: 1696 1697On host grasp.insa-lyon.fr (UUCP host name "grasp"), the following 1698summarizes the sender rewriting for various mailers. 1699 1700Mailer sender rewriting in the envelope 1701------ ------ ------------------------- 1702uucp-{old,new} wolf grasp!wolf 1703uucp-dom wolf wolf@grasp.insa-lyon.fr 1704uucp-uudom wolf grasp.insa-lyon.fr!wolf 1705 1706uucp-{old,new} wolf@fr.net grasp!fr.net!wolf 1707uucp-dom wolf@fr.net wolf@fr.net 1708uucp-uudom wolf@fr.net fr.net!wolf 1709 1710uucp-{old,new} somehost!wolf grasp!somehost!wolf 1711uucp-dom somehost!wolf somehost!wolf@grasp.insa-lyon.fr 1712uucp-uudom somehost!wolf grasp.insa-lyon.fr!somehost!wolf 1713 1714If you are using one of the domainized UUCP mailers, you really want 1715to convert all UUCP addresses to domain format -- otherwise, it will 1716do it for you (and probably not the way you expected). For example, 1717if you have the address foo!bar!baz (and you are not sending to foo), 1718the heuristics will add the @uucp.relay.name or @local.host.name to 1719this address. However, if you map foo to foo.host.name first, it 1720will not add the local hostname. You can do this using the uucpdomain 1721feature. 1722 1723 1724+-------------------+ 1725| TWEAKING RULESETS | 1726+-------------------+ 1727 1728For more complex configurations, you can define special rules. 1729The macro LOCAL_RULE_3 introduces rules that are used in canonicalizing 1730the names. Any modifications made here are reflected in the header. 1731 1732A common use is to convert old UUCP addresses to SMTP addresses using 1733the UUCPSMTP macro. For example: 1734 1735 LOCAL_RULE_3 1736 UUCPSMTP(`decvax', `decvax.dec.com') 1737 UUCPSMTP(`research', `research.att.com') 1738 1739will cause addresses of the form "decvax!user" and "research!user" 1740to be converted to "user@decvax.dec.com" and "user@research.att.com" 1741respectively. 1742 1743This could also be used to look up hosts in a database map: 1744 1745 LOCAL_RULE_3 1746 R$* < @ $+ > $* $: $1 < @ $(hostmap $2 $) > $3 1747 1748This map would be defined in the LOCAL_CONFIG portion, as shown below. 1749 1750Similarly, LOCAL_RULE_0 can be used to introduce new parsing rules. 1751For example, new rules are needed to parse hostnames that you accept 1752via MX records. For example, you might have: 1753 1754 LOCAL_RULE_0 1755 R$+ <@ host.dom.ain.> $#uucp $@ cnmat $: $1 < @ host.dom.ain.> 1756 1757You would use this if you had installed an MX record for cnmat.Berkeley.EDU 1758pointing at this host; this rule catches the message and forwards it on 1759using UUCP. 1760 1761You can also tweak rulesets 1 and 2 using LOCAL_RULE_1 and LOCAL_RULE_2. 1762These rulesets are normally empty. 1763 1764A similar macro is LOCAL_CONFIG. This introduces lines added after the 1765boilerplate option setting but before rulesets. Do not declare rulesets in 1766the LOCAL_CONFIG section. It can be used to declare local database maps or 1767whatever. For example: 1768 1769 LOCAL_CONFIG 1770 Khostmap hash /etc/mail/hostmap 1771 Kyplocal nis -m hosts.byname 1772 1773 1774+---------------------------+ 1775| MASQUERADING AND RELAYING | 1776+---------------------------+ 1777 1778You can have your host masquerade as another using 1779 1780 MASQUERADE_AS(`host.domain') 1781 1782This causes mail being sent to be labeled as coming from the 1783indicated host.domain, rather than $j. One normally masquerades as 1784one of one's own subdomains (for example, it's unlikely that 1785Berkeley would choose to masquerade as an MIT site). This 1786behaviour is modified by a plethora of FEATUREs; in particular, see 1787masquerade_envelope, allmasquerade, limited_masquerade, and 1788masquerade_entire_domain. 1789 1790The masquerade name is not normally canonified, so it is important 1791that it be your One True Name, that is, fully qualified and not a 1792CNAME. However, if you use a CNAME, the receiving side may canonify 1793it for you, so don't think you can cheat CNAME mapping this way. 1794 1795Normally the only addresses that are masqueraded are those that come 1796from this host (that is, are either unqualified or in class {w}, the list 1797of local domain names). You can augment this list, which is realized 1798by class {M} using 1799 1800 MASQUERADE_DOMAIN(`otherhost.domain') 1801 1802The effect of this is that although mail to user@otherhost.domain 1803will not be delivered locally, any mail including any user@otherhost.domain 1804will, when relayed, be rewritten to have the MASQUERADE_AS address. 1805This can be a space-separated list of names. 1806 1807If these names are in a file, you can use 1808 1809 MASQUERADE_DOMAIN_FILE(`filename') 1810 1811to read the list of names from the indicated file (i.e., to add 1812elements to class {M}). 1813 1814To exempt hosts or subdomains from being masqueraded, you can use 1815 1816 MASQUERADE_EXCEPTION(`host.domain') 1817 1818This can come handy if you want to masquerade a whole domain 1819except for one (or a few) host(s). If these names are in a file, 1820you can use 1821 1822 MASQUERADE_EXCEPTION_FILE(`filename') 1823 1824Normally only header addresses are masqueraded. If you want to 1825masquerade the envelope as well, use 1826 1827 FEATURE(`masquerade_envelope') 1828 1829There are always users that need to be "exposed" -- that is, their 1830internal site name should be displayed instead of the masquerade name. 1831Root is an example (which has been "exposed" by default prior to 8.10). 1832You can add users to this list using 1833 1834 EXPOSED_USER(`usernames') 1835 1836This adds users to class {E}; you could also use 1837 1838 EXPOSED_USER_FILE(`filename') 1839 1840You can also arrange to relay all unqualified names (that is, names 1841without @host) to a relay host. For example, if you have a central 1842email server, you might relay to that host so that users don't have 1843to have .forward files or aliases. You can do this using 1844 1845 define(`LOCAL_RELAY', `mailer:hostname') 1846 1847The ``mailer:'' can be omitted, in which case the mailer defaults to 1848"relay". There are some user names that you don't want relayed, perhaps 1849because of local aliases. A common example is root, which may be 1850locally aliased. You can add entries to this list using 1851 1852 LOCAL_USER(`usernames') 1853 1854This adds users to class {L}; you could also use 1855 1856 LOCAL_USER_FILE(`filename') 1857 1858If you want all incoming mail sent to a centralized hub, as for a 1859shared /var/spool/mail scheme, use 1860 1861 define(`MAIL_HUB', `mailer:hostname') 1862 1863Again, ``mailer:'' defaults to "relay". If you define both LOCAL_RELAY 1864and MAIL_HUB _AND_ you have FEATURE(`stickyhost'), unqualified names will 1865be sent to the LOCAL_RELAY and other local names will be sent to MAIL_HUB. 1866Note: there is a (long standing) bug which keeps this combination from 1867working for addresses of the form user+detail. 1868Names in class {L} will be delivered locally, so you MUST have aliases or 1869.forward files for them. 1870 1871For example, if you are on machine mastodon.CS.Berkeley.EDU and you have 1872FEATURE(`stickyhost'), the following combinations of settings will have the 1873indicated effects: 1874 1875email sent to.... eric eric@mastodon.CS.Berkeley.EDU 1876 1877LOCAL_RELAY set to mail.CS.Berkeley.EDU (delivered locally) 1878mail.CS.Berkeley.EDU (no local aliasing) (aliasing done) 1879 1880MAIL_HUB set to mammoth.CS.Berkeley.EDU mammoth.CS.Berkeley.EDU 1881mammoth.CS.Berkeley.EDU (aliasing done) (aliasing done) 1882 1883Both LOCAL_RELAY and mail.CS.Berkeley.EDU mammoth.CS.Berkeley.EDU 1884MAIL_HUB set as above (no local aliasing) (aliasing done) 1885 1886If you do not have FEATURE(`stickyhost') set, then LOCAL_RELAY and 1887MAIL_HUB act identically, with MAIL_HUB taking precedence. 1888 1889If you want all outgoing mail to go to a central relay site, define 1890SMART_HOST as well. Briefly: 1891 1892 LOCAL_RELAY applies to unqualified names (e.g., "eric"). 1893 MAIL_HUB applies to names qualified with the name of the 1894 local host (e.g., "eric@mastodon.CS.Berkeley.EDU"). 1895 SMART_HOST applies to names qualified with other hosts or 1896 bracketed addresses (e.g., "eric@mastodon.CS.Berkeley.EDU" 1897 or "eric@[127.0.0.1]"). 1898 1899However, beware that other relays (e.g., UUCP_RELAY, BITNET_RELAY, 1900DECNET_RELAY, and FAX_RELAY) take precedence over SMART_HOST, so if you 1901really want absolutely everything to go to a single central site you will 1902need to unset all the other relays -- or better yet, find or build a 1903minimal config file that does this. 1904 1905For duplicate suppression to work properly, the host name is best 1906specified with a terminal dot: 1907 1908 define(`MAIL_HUB', `host.domain.') 1909 note the trailing dot ---^ 1910 1911 1912+-------------------------------------------+ 1913| USING LDAP FOR ALIASES, MAPS, AND CLASSES | 1914+-------------------------------------------+ 1915 1916LDAP can be used for aliases, maps, and classes by either specifying your 1917own LDAP map specification or using the built-in default LDAP map 1918specification. The built-in default specifications all provide lookups 1919which match against either the machine's fully qualified hostname (${j}) or 1920a "cluster". The cluster allows you to share LDAP entries among a large 1921number of machines without having to enter each of the machine names into 1922each LDAP entry. To set the LDAP cluster name to use for a particular 1923machine or set of machines, set the confLDAP_CLUSTER m4 variable to a 1924unique name. For example: 1925 1926 define(`confLDAP_CLUSTER', `Servers') 1927 1928Here, the word `Servers' will be the cluster name. As an example, assume 1929that smtp.sendmail.org, etrn.sendmail.org, and mx.sendmail.org all belong 1930to the Servers cluster. 1931 1932Some of the LDAP LDIF examples below show use of the Servers cluster. 1933Every entry must have either a sendmailMTAHost or sendmailMTACluster 1934attribute or it will be ignored. Be careful as mixing clusters and 1935individual host records can have surprising results (see the CAUTION 1936sections below). 1937 1938See the file cf/sendmail.schema for the actual LDAP schemas. Note that 1939this schema (and therefore the lookups and examples below) is experimental 1940at this point as it has had little public review. Therefore, it may change 1941in future versions. Feedback via sendmail-YYYY@support.sendmail.org is 1942encouraged (replace YYYY with the current year, e.g., 2005). 1943 1944------- 1945Aliases 1946------- 1947 1948The ALIAS_FILE (O AliasFile) option can be set to use LDAP for alias 1949lookups. To use the default schema, simply use: 1950 1951 define(`ALIAS_FILE', `ldap:') 1952 1953By doing so, you will use the default schema which expands to a map 1954declared as follows: 1955 1956 ldap -k (&(objectClass=sendmailMTAAliasObject) 1957 (sendmailMTAAliasGrouping=aliases) 1958 (|(sendmailMTACluster=${sendmailMTACluster}) 1959 (sendmailMTAHost=$j)) 1960 (sendmailMTAKey=%0)) 1961 -v sendmailMTAAliasValue,sendmailMTAAliasSearch:FILTER:sendmailMTAAliasObject,sendmailMTAAliasURL:URL:sendmailMTAAliasObject 1962 1963 1964NOTE: The macros shown above ${sendmailMTACluster} and $j are not actually 1965used when the binary expands the `ldap:' token as the AliasFile option is 1966not actually macro-expanded when read from the sendmail.cf file. 1967 1968Example LDAP LDIF entries might be: 1969 1970 dn: sendmailMTAKey=sendmail-list, dc=sendmail, dc=org 1971 objectClass: sendmailMTA 1972 objectClass: sendmailMTAAlias 1973 objectClass: sendmailMTAAliasObject 1974 sendmailMTAAliasGrouping: aliases 1975 sendmailMTAHost: etrn.sendmail.org 1976 sendmailMTAKey: sendmail-list 1977 sendmailMTAAliasValue: ca@example.org 1978 sendmailMTAAliasValue: eric 1979 sendmailMTAAliasValue: gshapiro@example.com 1980 1981 dn: sendmailMTAKey=owner-sendmail-list, dc=sendmail, dc=org 1982 objectClass: sendmailMTA 1983 objectClass: sendmailMTAAlias 1984 objectClass: sendmailMTAAliasObject 1985 sendmailMTAAliasGrouping: aliases 1986 sendmailMTAHost: etrn.sendmail.org 1987 sendmailMTAKey: owner-sendmail-list 1988 sendmailMTAAliasValue: eric 1989 1990 dn: sendmailMTAKey=postmaster, dc=sendmail, dc=org 1991 objectClass: sendmailMTA 1992 objectClass: sendmailMTAAlias 1993 objectClass: sendmailMTAAliasObject 1994 sendmailMTAAliasGrouping: aliases 1995 sendmailMTACluster: Servers 1996 sendmailMTAKey: postmaster 1997 sendmailMTAAliasValue: eric 1998 1999Here, the aliases sendmail-list and owner-sendmail-list will be available 2000only on etrn.sendmail.org but the postmaster alias will be available on 2001every machine in the Servers cluster (including etrn.sendmail.org). 2002 2003CAUTION: aliases are additive so that entries like these: 2004 2005 dn: sendmailMTAKey=bob, dc=sendmail, dc=org 2006 objectClass: sendmailMTA 2007 objectClass: sendmailMTAAlias 2008 objectClass: sendmailMTAAliasObject 2009 sendmailMTAAliasGrouping: aliases 2010 sendmailMTACluster: Servers 2011 sendmailMTAKey: bob 2012 sendmailMTAAliasValue: eric 2013 2014 dn: sendmailMTAKey=bobetrn, dc=sendmail, dc=org 2015 objectClass: sendmailMTA 2016 objectClass: sendmailMTAAlias 2017 objectClass: sendmailMTAAliasObject 2018 sendmailMTAAliasGrouping: aliases 2019 sendmailMTAHost: etrn.sendmail.org 2020 sendmailMTAKey: bob 2021 sendmailMTAAliasValue: gshapiro 2022 2023would mean that on all of the hosts in the cluster, mail to bob would go to 2024eric EXCEPT on etrn.sendmail.org in which case it would go to BOTH eric and 2025gshapiro. 2026 2027If you prefer not to use the default LDAP schema for your aliases, you can 2028specify the map parameters when setting ALIAS_FILE. For example: 2029 2030 define(`ALIAS_FILE', `ldap:-k (&(objectClass=mailGroup)(mail=%0)) -v mgrpRFC822MailMember') 2031 2032---- 2033Maps 2034---- 2035 2036FEATURE()'s which take an optional map definition argument (e.g., access, 2037mailertable, virtusertable, etc.) can instead take the special keyword 2038`LDAP', e.g.: 2039 2040 FEATURE(`access_db', `LDAP') 2041 FEATURE(`virtusertable', `LDAP') 2042 2043When this keyword is given, that map will use LDAP lookups consisting of 2044the objectClass sendmailMTAClassObject, the attribute sendmailMTAMapName 2045with the map name, a search attribute of sendmailMTAKey, and the value 2046attribute sendmailMTAMapValue. 2047 2048The values for sendmailMTAMapName are: 2049 2050 FEATURE() sendmailMTAMapName 2051 --------- ------------------ 2052 access_db access 2053 authinfo authinfo 2054 bitdomain bitdomain 2055 domaintable domain 2056 genericstable generics 2057 mailertable mailer 2058 uucpdomain uucpdomain 2059 virtusertable virtuser 2060 2061For example, FEATURE(`mailertable', `LDAP') would use the map definition: 2062 2063 Kmailertable ldap -k (&(objectClass=sendmailMTAMapObject) 2064 (sendmailMTAMapName=mailer) 2065 (|(sendmailMTACluster=${sendmailMTACluster}) 2066 (sendmailMTAHost=$j)) 2067 (sendmailMTAKey=%0)) 2068 -1 -v sendmailMTAMapValue,sendmailMTAMapSearch:FILTER:sendmailMTAMapObject,sendmailMTAMapURL:URL:sendmailMTAMapObject 2069 2070An example LDAP LDIF entry using this map might be: 2071 2072 dn: sendmailMTAMapName=mailer, dc=sendmail, dc=org 2073 objectClass: sendmailMTA 2074 objectClass: sendmailMTAMap 2075 sendmailMTACluster: Servers 2076 sendmailMTAMapName: mailer 2077 2078 dn: sendmailMTAKey=example.com, sendmailMTAMapName=mailer, dc=sendmail, dc=org 2079 objectClass: sendmailMTA 2080 objectClass: sendmailMTAMap 2081 objectClass: sendmailMTAMapObject 2082 sendmailMTAMapName: mailer 2083 sendmailMTACluster: Servers 2084 sendmailMTAKey: example.com 2085 sendmailMTAMapValue: relay:[smtp.example.com] 2086 2087CAUTION: If your LDAP database contains the record above and *ALSO* a host 2088specific record such as: 2089 2090 dn: sendmailMTAKey=example.com@etrn, sendmailMTAMapName=mailer, dc=sendmail, dc=org 2091 objectClass: sendmailMTA 2092 objectClass: sendmailMTAMap 2093 objectClass: sendmailMTAMapObject 2094 sendmailMTAMapName: mailer 2095 sendmailMTAHost: etrn.sendmail.org 2096 sendmailMTAKey: example.com 2097 sendmailMTAMapValue: relay:[mx.example.com] 2098 2099then these entries will give unexpected results. When the lookup is done 2100on etrn.sendmail.org, the effect is that there is *NO* match at all as maps 2101require a single match. Since the host etrn.sendmail.org is also in the 2102Servers cluster, LDAP would return two answers for the example.com map key 2103in which case sendmail would treat this as no match at all. 2104 2105If you prefer not to use the default LDAP schema for your maps, you can 2106specify the map parameters when using the FEATURE(). For example: 2107 2108 FEATURE(`access_db', `ldap:-1 -k (&(objectClass=mapDatabase)(key=%0)) -v value') 2109 2110------- 2111Classes 2112------- 2113 2114Normally, classes can be filled via files or programs. As of 8.12, they 2115can also be filled via map lookups using a new syntax: 2116 2117 F{ClassName}mapkey@mapclass:mapspec 2118 2119mapkey is optional and if not provided the map key will be empty. This can 2120be used with LDAP to read classes from LDAP. Note that the lookup is only 2121done when sendmail is initially started. Use the special value `@LDAP' to 2122use the default LDAP schema. For example: 2123 2124 RELAY_DOMAIN_FILE(`@LDAP') 2125 2126would put all of the attribute sendmailMTAClassValue values of LDAP records 2127with objectClass sendmailMTAClass and an attribute sendmailMTAClassName of 2128'R' into class $={R}. In other words, it is equivalent to the LDAP map 2129specification: 2130 2131 F{R}@ldap:-k (&(objectClass=sendmailMTAClass) 2132 (sendmailMTAClassName=R) 2133 (|(sendmailMTACluster=${sendmailMTACluster}) 2134 (sendmailMTAHost=$j))) 2135 -v sendmailMTAClassValue,sendmailMTAClassSearch:FILTER:sendmailMTAClass,sendmailMTAClassURL:URL:sendmailMTAClass 2136 2137NOTE: The macros shown above ${sendmailMTACluster} and $j are not actually 2138used when the binary expands the `@LDAP' token as class declarations are 2139not actually macro-expanded when read from the sendmail.cf file. 2140 2141This can be used with class related commands such as RELAY_DOMAIN_FILE(), 2142MASQUERADE_DOMAIN_FILE(), etc: 2143 2144 Command sendmailMTAClassName 2145 ------- -------------------- 2146 CANONIFY_DOMAIN_FILE() Canonify 2147 EXPOSED_USER_FILE() E 2148 GENERICS_DOMAIN_FILE() G 2149 LDAPROUTE_DOMAIN_FILE() LDAPRoute 2150 LDAPROUTE_EQUIVALENT_FILE() LDAPRouteEquiv 2151 LOCAL_USER_FILE() L 2152 MASQUERADE_DOMAIN_FILE() M 2153 MASQUERADE_EXCEPTION_FILE() N 2154 RELAY_DOMAIN_FILE() R 2155 VIRTUSER_DOMAIN_FILE() VirtHost 2156 2157You can also add your own as any 'F'ile class of the form: 2158 2159 F{ClassName}@LDAP 2160 ^^^^^^^^^ 2161will use "ClassName" for the sendmailMTAClassName. 2162 2163An example LDAP LDIF entry would look like: 2164 2165 dn: sendmailMTAClassName=R, dc=sendmail, dc=org 2166 objectClass: sendmailMTA 2167 objectClass: sendmailMTAClass 2168 sendmailMTACluster: Servers 2169 sendmailMTAClassName: R 2170 sendmailMTAClassValue: sendmail.org 2171 sendmailMTAClassValue: example.com 2172 sendmailMTAClassValue: 10.56.23 2173 2174CAUTION: If your LDAP database contains the record above and *ALSO* a host 2175specific record such as: 2176 2177 dn: sendmailMTAClassName=R@etrn.sendmail.org, dc=sendmail, dc=org 2178 objectClass: sendmailMTA 2179 objectClass: sendmailMTAClass 2180 sendmailMTAHost: etrn.sendmail.org 2181 sendmailMTAClassName: R 2182 sendmailMTAClassValue: example.com 2183 2184the result will be similar to the aliases caution above. When the lookup 2185is done on etrn.sendmail.org, $={R} would contain all of the entries (from 2186both the cluster match and the host match). In other words, the effective 2187is additive. 2188 2189If you prefer not to use the default LDAP schema for your classes, you can 2190specify the map parameters when using the class command. For example: 2191 2192 VIRTUSER_DOMAIN_FILE(`@ldap:-k (&(objectClass=virtHosts)(host=*)) -v host') 2193 2194Remember, macros can not be used in a class declaration as the binary does 2195not expand them. 2196 2197 2198+--------------+ 2199| LDAP ROUTING | 2200+--------------+ 2201 2202FEATURE(`ldap_routing') can be used to implement the IETF Internet Draft 2203LDAP Schema for Intranet Mail Routing 2204(draft-lachman-laser-ldap-mail-routing-01). This feature enables 2205LDAP-based rerouting of a particular address to either a different host 2206or a different address. The LDAP lookup is first attempted on the full 2207address (e.g., user@example.com) and then on the domain portion 2208(e.g., @example.com). Be sure to setup your domain for LDAP routing using 2209LDAPROUTE_DOMAIN(), e.g.: 2210 2211 LDAPROUTE_DOMAIN(`example.com') 2212 2213Additionally, you can specify equivalent domains for LDAP routing using 2214LDAPROUTE_EQUIVALENT() and LDAPROUTE_EQUIVALENT_FILE(). 'Equivalent' 2215hostnames are mapped to $M (the masqueraded hostname for the server) before 2216the LDAP query. For example, if the mail is addressed to 2217user@host1.example.com, normally the LDAP lookup would only be done for 2218'user@host1.example.com' and '@host1.example.com'. However, if 2219LDAPROUTE_EQUIVALENT(`host1.example.com') is used, the lookups would also be 2220done on 'user@example.com' and '@example.com' after attempting the 2221host1.example.com lookups. 2222 2223By default, the feature will use the schemas as specified in the draft 2224and will not reject addresses not found by the LDAP lookup. However, 2225this behavior can be changed by giving additional arguments to the FEATURE() 2226command: 2227 2228 FEATURE(`ldap_routing', <mailHost>, <mailRoutingAddress>, <bounce>, 2229 <detail>, <nodomain>, <tempfail>) 2230 2231where <mailHost> is a map definition describing how to lookup an alternative 2232mail host for a particular address; <mailRoutingAddress> is a map definition 2233describing how to lookup an alternative address for a particular address; 2234the <bounce> argument, if present and not the word "passthru", dictates 2235that mail should be bounced if neither a mailHost nor mailRoutingAddress 2236is found, if set to "sendertoo", the sender will be rejected if not 2237found in LDAP; and <detail> indicates what actions to take if the address 2238contains +detail information -- `strip' tries the lookup with the +detail 2239and if no matches are found, strips the +detail and tries the lookup again; 2240`preserve', does the same as `strip' but if a mailRoutingAddress match is 2241found, the +detail information is copied to the new address; the <nodomain> 2242argument, if present, will prevent the @domain lookup if the full 2243address is not found in LDAP; the <tempfail> argument, if set to 2244"tempfail", instructs the rules to give an SMTP 4XX temporary 2245error if the LDAP server gives the MTA a temporary failure, or if set to 2246"queue" (the default), the MTA will locally queue the mail. 2247 2248The default <mailHost> map definition is: 2249 2250 ldap -1 -T<TMPF> -v mailHost -k (&(objectClass=inetLocalMailRecipient) 2251 (mailLocalAddress=%0)) 2252 2253The default <mailRoutingAddress> map definition is: 2254 2255 ldap -1 -T<TMPF> -v mailRoutingAddress 2256 -k (&(objectClass=inetLocalMailRecipient) 2257 (mailLocalAddress=%0)) 2258 2259Note that neither includes the LDAP server hostname (-h server) or base DN 2260(-b o=org,c=COUNTRY), both necessary for LDAP queries. It is presumed that 2261your .mc file contains a setting for the confLDAP_DEFAULT_SPEC option with 2262these settings. If this is not the case, the map definitions should be 2263changed as described above. The "-T<TMPF>" is required in any user 2264specified map definition to catch temporary errors. 2265 2266The following possibilities exist as a result of an LDAP lookup on an 2267address: 2268 2269 mailHost is mailRoutingAddress is Results in 2270 ----------- --------------------- ---------- 2271 set to a set mail delivered to 2272 "local" host mailRoutingAddress 2273 2274 set to a not set delivered to 2275 "local" host original address 2276 2277 set to a set mailRoutingAddress 2278 remote host relayed to mailHost 2279 2280 set to a not set original address 2281 remote host relayed to mailHost 2282 2283 not set set mail delivered to 2284 mailRoutingAddress 2285 2286 not set not set delivered to 2287 original address *OR* 2288 bounced as unknown user 2289 2290The term "local" host above means the host specified is in class {w}. If 2291the result would mean sending the mail to a different host, that host is 2292looked up in the mailertable before delivery. 2293 2294Note that the last case depends on whether the third argument is given 2295to the FEATURE() command. The default is to deliver the message to the 2296original address. 2297 2298The LDAP entries should be set up with an objectClass of 2299inetLocalMailRecipient and the address be listed in a mailLocalAddress 2300attribute. If present, there must be only one mailHost attribute and it 2301must contain a fully qualified host name as its value. Similarly, if 2302present, there must be only one mailRoutingAddress attribute and it must 2303contain an RFC 822 compliant address. Some example LDAP records (in LDIF 2304format): 2305 2306 dn: uid=tom, o=example.com, c=US 2307 objectClass: inetLocalMailRecipient 2308 mailLocalAddress: tom@example.com 2309 mailRoutingAddress: thomas@mailhost.example.com 2310 2311This would deliver mail for tom@example.com to thomas@mailhost.example.com. 2312 2313 dn: uid=dick, o=example.com, c=US 2314 objectClass: inetLocalMailRecipient 2315 mailLocalAddress: dick@example.com 2316 mailHost: eng.example.com 2317 2318This would relay mail for dick@example.com to the same address but redirect 2319the mail to MX records listed for the host eng.example.com (unless the 2320mailertable overrides). 2321 2322 dn: uid=harry, o=example.com, c=US 2323 objectClass: inetLocalMailRecipient 2324 mailLocalAddress: harry@example.com 2325 mailHost: mktmail.example.com 2326 mailRoutingAddress: harry@mkt.example.com 2327 2328This would relay mail for harry@example.com to the MX records listed for 2329the host mktmail.example.com using the new address harry@mkt.example.com 2330when talking to that host. 2331 2332 dn: uid=virtual.example.com, o=example.com, c=US 2333 objectClass: inetLocalMailRecipient 2334 mailLocalAddress: @virtual.example.com 2335 mailHost: server.example.com 2336 mailRoutingAddress: virtual@example.com 2337 2338This would send all mail destined for any username @virtual.example.com to 2339the machine server.example.com's MX servers and deliver to the address 2340virtual@example.com on that relay machine. 2341 2342 2343+---------------------------------+ 2344| ANTI-SPAM CONFIGURATION CONTROL | 2345+---------------------------------+ 2346 2347The primary anti-spam features available in sendmail are: 2348 2349* Relaying is denied by default. 2350* Better checking on sender information. 2351* Access database. 2352* Header checks. 2353 2354Relaying (transmission of messages from a site outside your host (class 2355{w}) to another site except yours) is denied by default. Note that this 2356changed in sendmail 8.9; previous versions allowed relaying by default. 2357If you really want to revert to the old behaviour, you will need to use 2358FEATURE(`promiscuous_relay'). You can allow certain domains to relay 2359through your server by adding their domain name or IP address to class 2360{R} using RELAY_DOMAIN() and RELAY_DOMAIN_FILE() or via the access database 2361(described below). Note that IPv6 addresses must be prefaced with "IPv6:". 2362The file consists (like any other file based class) of entries listed on 2363separate lines, e.g., 2364 2365 sendmail.org 2366 128.32 2367 IPv6:2002:c0a8:02c7 2368 IPv6:2002:c0a8:51d2::23f4 2369 host.mydomain.com 2370 [UNIX:localhost] 2371 2372Notice: the last entry allows relaying for connections via a UNIX 2373socket to the MTA/MSP. This might be necessary if your configuration 2374doesn't allow relaying by other means in that case, e.g., by having 2375localhost.$m in class {R} (make sure $m is not just a top level 2376domain). 2377 2378If you use 2379 2380 FEATURE(`relay_entire_domain') 2381 2382then any host in any of your local domains (that is, class {m}) 2383will be relayed (that is, you will accept mail either to or from any 2384host in your domain). 2385 2386You can also allow relaying based on the MX records of the host 2387portion of an incoming recipient address by using 2388 2389 FEATURE(`relay_based_on_MX') 2390 2391For example, if your server receives a recipient of user@domain.com 2392and domain.com lists your server in its MX records, the mail will be 2393accepted for relay to domain.com. This feature may cause problems 2394if MX lookups for the recipient domain are slow or time out. In that 2395case, mail will be temporarily rejected. It is usually better to 2396maintain a list of hosts/domains for which the server acts as relay. 2397Note also that this feature will stop spammers from using your host 2398to relay spam but it will not stop outsiders from using your server 2399as a relay for their site (that is, they set up an MX record pointing 2400to your mail server, and you will relay mail addressed to them 2401without any prior arrangement). Along the same lines, 2402 2403 FEATURE(`relay_local_from') 2404 2405will allow relaying if the sender specifies a return path (i.e. 2406MAIL FROM:<user@domain>) domain which is a local domain. This is a 2407dangerous feature as it will allow spammers to spam using your mail 2408server by simply specifying a return address of user@your.domain.com. 2409It should not be used unless absolutely necessary. 2410A slightly better solution is 2411 2412 FEATURE(`relay_mail_from') 2413 2414which allows relaying if the mail sender is listed as RELAY in the 2415access map. If an optional argument `domain' (this is the literal 2416word `domain', not a placeholder) is given, the domain portion of 2417the mail sender is also checked to allowing relaying. This option 2418only works together with the tag From: for the LHS of the access 2419map entries. This feature allows spammers to abuse your mail server 2420by specifying a return address that you enabled in your access file. 2421This may be harder to figure out for spammers, but it should not 2422be used unless necessary. Instead use SMTP AUTH or STARTTLS to 2423allow relaying for roaming users. 2424 2425 2426If source routing is used in the recipient address (e.g., 2427RCPT TO:<user%site.com@othersite.com>), sendmail will check 2428user@site.com for relaying if othersite.com is an allowed relay host 2429in either class {R}, class {m} if FEATURE(`relay_entire_domain') is used, 2430or the access database if FEATURE(`access_db') is used. To prevent 2431the address from being stripped down, use: 2432 2433 FEATURE(`loose_relay_check') 2434 2435If you think you need to use this feature, you probably do not. This 2436should only be used for sites which have no control over the addresses 2437that they provide a gateway for. Use this FEATURE with caution as it 2438can allow spammers to relay through your server if not setup properly. 2439 2440NOTICE: It is possible to relay mail through a system which the anti-relay 2441rules do not prevent: the case of a system that does use FEATURE(`nouucp', 2442`nospecial') (system A) and relays local messages to a mail hub (e.g., via 2443LOCAL_RELAY or LUSER_RELAY) (system B). If system B doesn't use 2444FEATURE(`nouucp') at all, addresses of the form 2445<example.net!user@local.host> would be relayed to <user@example.net>. 2446System A doesn't recognize `!' as an address separator and therefore 2447forwards it to the mail hub which in turns relays it because it came from 2448a trusted local host. So if a mailserver allows UUCP (bang-format) 2449addresses, all systems from which it allows relaying should do the same 2450or reject those addresses. 2451 2452As of 8.9, sendmail will refuse mail if the MAIL FROM: parameter has 2453an unresolvable domain (i.e., one that DNS, your local name service, 2454or special case rules in ruleset 3 cannot locate). This also applies 2455to addresses that use domain literals, e.g., <user@[1.2.3.4]>, if the 2456IP address can't be mapped to a host name. If you want to continue 2457to accept such domains, e.g., because you are inside a firewall that 2458has only a limited view of the Internet host name space (note that you 2459will not be able to return mail to them unless you have some "smart 2460host" forwarder), use 2461 2462 FEATURE(`accept_unresolvable_domains') 2463 2464Alternatively, you can allow specific addresses by adding them to 2465the access map, e.g., 2466 2467 From:unresolvable.domain OK 2468 From:[1.2.3.4] OK 2469 From:[1.2.4] OK 2470 2471Notice: domains which are temporarily unresolvable are (temporarily) 2472rejected with a 451 reply code. If those domains should be accepted 2473(which is discouraged) then you can use 2474 2475 LOCAL_CONFIG 2476 C{ResOk}TEMP 2477 2478sendmail will also refuse mail if the MAIL FROM: parameter is not 2479fully qualified (i.e., contains a domain as well as a user). If you 2480want to continue to accept such senders, use 2481 2482 FEATURE(`accept_unqualified_senders') 2483 2484Setting the DaemonPortOptions modifier 'u' overrides the default behavior, 2485i.e., unqualified addresses are accepted even without this FEATURE. If 2486this FEATURE is not used, the DaemonPortOptions modifier 'f' can be used 2487to enforce fully qualified domain names. 2488 2489An ``access'' database can be created to accept or reject mail from 2490selected domains. For example, you may choose to reject all mail 2491originating from known spammers. To enable such a database, use 2492 2493 FEATURE(`access_db') 2494 2495Notice: the access database is applied to the envelope addresses 2496and the connection information, not to the header. 2497 2498The FEATURE macro can accept as second parameter the key file 2499definition for the database; for example 2500 2501 FEATURE(`access_db', `hash -T<TMPF> /etc/mail/access_map') 2502 2503Notice: If a second argument is specified it must contain the option 2504`-T<TMPF>' as shown above. The optional parameters may be 2505 2506 `skip' enables SKIP as value part (see below). 2507 `lookupdotdomain' another way to enable the feature of the 2508 same name (see above). 2509 `relaytofulladdress' enable entries of the form 2510 To:user@example.com RELAY 2511 to allow relaying to just a specific 2512 e-mail address instead of an entire domain. 2513 2514Remember, since /etc/mail/access is a database, after creating the text 2515file as described below, you must use makemap to create the database 2516map. For example: 2517 2518 makemap hash /etc/mail/access < /etc/mail/access 2519 2520The table itself uses e-mail addresses, domain names, and network 2521numbers as keys. Note that IPv6 addresses must be prefaced with "IPv6:". 2522For example, 2523 2524 From:spammer@aol.com REJECT 2525 From:cyberspammer.com REJECT 2526 Connect:cyberspammer.com REJECT 2527 Connect:TLD REJECT 2528 Connect:192.168.212 REJECT 2529 Connect:IPv6:2002:c0a8:02c7 RELAY 2530 Connect:IPv6:2002:c0a8:51d2::23f4 REJECT 2531 2532would refuse mail from spammer@aol.com, any user from cyberspammer.com 2533(or any host within the cyberspammer.com domain), any host in the entire 2534top level domain TLD, 192.168.212.* network, and the IPv6 address 25352002:c0a8:51d2::23f4. It would allow relay for the IPv6 network 25362002:c0a8:02c7::/48. 2537 2538Entries in the access map should be tagged according to their type. 2539Three tags are available: 2540 2541 Connect: connection information (${client_addr}, ${client_name}) 2542 From: envelope sender 2543 To: envelope recipient 2544 2545Notice: untagged entries are deprecated. 2546 2547If the required item is looked up in a map, it will be tried first 2548with the corresponding tag in front, then (as fallback to enable 2549backward compatibility) without any tag, unless the specific feature 2550requires a tag. For example, 2551 2552 From:spammer@some.dom REJECT 2553 To:friend.domain RELAY 2554 Connect:friend.domain OK 2555 Connect:from.domain RELAY 2556 From:good@another.dom OK 2557 From:another.dom REJECT 2558 2559This would deny mails from spammer@some.dom but you could still 2560send mail to that address even if FEATURE(`blacklist_recipients') 2561is enabled. Your system will allow relaying to friend.domain, but 2562not from it (unless enabled by other means). Connections from that 2563domain will be allowed even if it ends up in one of the DNS based 2564rejection lists. Relaying is enabled from from.domain but not to 2565it (since relaying is based on the connection information for 2566outgoing relaying, the tag Connect: must be used; for incoming 2567relaying, which is based on the recipient address, To: must be 2568used). The last two entries allow mails from good@another.dom but 2569reject mail from all other addresses with another.dom as domain 2570part. 2571 2572 2573The value part of the map can contain: 2574 2575 OK Accept mail even if other rules in the running 2576 ruleset would reject it, for example, if the domain 2577 name is unresolvable. "Accept" does not mean 2578 "relay", but at most acceptance for local 2579 recipients. That is, OK allows less than RELAY. 2580 RELAY Accept mail addressed to the indicated domain 2581 (or address if `relaytofulladdress' is set) or 2582 received from the indicated domain for relaying 2583 through your SMTP server. RELAY also serves as 2584 an implicit OK for the other checks. 2585 REJECT Reject the sender or recipient with a general 2586 purpose message. 2587 DISCARD Discard the message completely using the 2588 $#discard mailer. If it is used in check_compat, 2589 it affects only the designated recipient, not 2590 the whole message as it does in all other cases. 2591 This should only be used if really necessary. 2592 SKIP This can only be used for host/domain names 2593 and IP addresses/nets. It will abort the current 2594 search for this entry without accepting or rejecting 2595 it but causing the default action. 2596 ### any text where ### is an RFC 821 compliant error code and 2597 "any text" is a message to return for the command. 2598 The entire string should be quoted to avoid 2599 surprises: 2600 2601 "### any text" 2602 2603 Otherwise sendmail formats the text as email 2604 addresses, e.g., it may remove spaces. 2605 This type is deprecated, use one of the two 2606 ERROR: entries below instead. 2607 ERROR:### any text 2608 as above, but useful to mark error messages as such. 2609 If quotes need to be used to avoid modifications 2610 (see above), they should be placed like this: 2611 2612 ERROR:"### any text" 2613 2614 ERROR:D.S.N:### any text 2615 where D.S.N is an RFC 1893 compliant error code 2616 and the rest as above. If quotes need to be used 2617 to avoid modifications, they should be placed 2618 like this: 2619 2620 ERROR:D.S.N:"### any text" 2621 2622 QUARANTINE:any text 2623 Quarantine the message using the given text as the 2624 quarantining reason. 2625 2626For example: 2627 2628 From:cyberspammer.com ERROR:"550 We don't accept mail from spammers" 2629 From:okay.cyberspammer.com OK 2630 Connect:sendmail.org RELAY 2631 To:sendmail.org RELAY 2632 Connect:128.32 RELAY 2633 Connect:128.32.2 SKIP 2634 Connect:IPv6:1:2:3:4:5:6:7 RELAY 2635 Connect:suspicious.example.com QUARANTINE:Mail from suspicious host 2636 Connect:[127.0.0.3] OK 2637 Connect:[IPv6:1:2:3:4:5:6:7:8] OK 2638 2639would accept mail from okay.cyberspammer.com, but would reject mail 2640from all other hosts at cyberspammer.com with the indicated message. 2641It would allow relaying mail from and to any hosts in the sendmail.org 2642domain, and allow relaying from the IPv6 1:2:3:4:5:6:7:* network 2643and from the 128.32.*.* network except for the 128.32.2.* network, 2644which shows how SKIP is useful to exempt subnets/subdomains. The 2645last two entries are for checks against ${client_name} if the IP 2646address doesn't resolve to a hostname (or is considered as "may be 2647forged"). That is, using square brackets means these are host 2648names, not network numbers. 2649 2650Warning: if you change the RFC 821 compliant error code from the default 2651value of 550, then you should probably also change the RFC 1893 compliant 2652error code to match it. For example, if you use 2653 2654 To:user@example.com ERROR:450 mailbox full 2655 2656the error returned would be "450 5.0.0 mailbox full" which is wrong. 2657Use "ERROR:4.2.2:450 mailbox full" instead. 2658 2659Note, UUCP users may need to add hostname.UUCP to the access database 2660or class {R}. 2661 2662If you also use: 2663 2664 FEATURE(`relay_hosts_only') 2665 2666then the above example will allow relaying for sendmail.org, but not 2667hosts within the sendmail.org domain. Note that this will also require 2668hosts listed in class {R} to be fully qualified host names. 2669 2670You can also use the access database to block sender addresses based on 2671the username portion of the address. For example: 2672 2673 From:FREE.STEALTH.MAILER@ ERROR:550 Spam not accepted 2674 2675Note that you must include the @ after the username to signify that 2676this database entry is for checking only the username portion of the 2677sender address. 2678 2679If you use: 2680 2681 FEATURE(`blacklist_recipients') 2682 2683then you can add entries to the map for local users, hosts in your 2684domains, or addresses in your domain which should not receive mail: 2685 2686 To:badlocaluser@ ERROR:550 Mailbox disabled for badlocaluser 2687 To:host.my.TLD ERROR:550 That host does not accept mail 2688 To:user@other.my.TLD ERROR:550 Mailbox disabled for this recipient 2689 2690This would prevent a recipient of badlocaluser in any of the local 2691domains (class {w}), any user at host.my.TLD, and the single address 2692user@other.my.TLD from receiving mail. Please note: a local username 2693must be now tagged with an @ (this is consistent with the check of 2694the sender address, and hence it is possible to distinguish between 2695hostnames and usernames). Enabling this feature will keep you from 2696sending mails to all addresses that have an error message or REJECT 2697as value part in the access map. Taking the example from above: 2698 2699 spammer@aol.com REJECT 2700 cyberspammer.com REJECT 2701 2702Mail can't be sent to spammer@aol.com or anyone at cyberspammer.com. 2703That's why tagged entries should be used. 2704 2705There are several DNS based blacklists which can be found by 2706querying a search engine. These are databases of spammers 2707maintained in DNS. To use such a database, specify 2708 2709 FEATURE(`dnsbl', `dnsbl.example.com') 2710 2711This will cause sendmail to reject mail from any site listed in the 2712DNS based blacklist. You must select a DNS based blacklist domain 2713to check by specifying an argument to the FEATURE. The default 2714error message is 2715 2716 Rejected: IP-ADDRESS listed at SERVER 2717 2718where IP-ADDRESS and SERVER are replaced by the appropriate 2719information. A second argument can be used to specify a different 2720text or action. For example, 2721 2722 FEATURE(`dnsbl', `dnsbl.example.com', `quarantine') 2723 2724would quarantine the message if the client IP address is listed 2725at `dnsbl.example.com'. 2726 2727By default, temporary lookup failures are ignored 2728and hence cause the connection not to be rejected by the DNS based 2729rejection list. This behavior can be changed by specifying a third 2730argument, which must be either `t' or a full error message. For 2731example: 2732 2733 FEATURE(`dnsbl', `dnsbl.example.com', `', 2734 `"451 Temporary lookup failure for " $&{client_addr} " in dnsbl.example.com"') 2735 2736If `t' is used, the error message is: 2737 2738 451 Temporary lookup failure of IP-ADDRESS at SERVER 2739 2740where IP-ADDRESS and SERVER are replaced by the appropriate 2741information. 2742 2743This FEATURE can be included several times to query different 2744DNS based rejection lists. 2745 2746Notice: to avoid checking your own local domains against those 2747blacklists, use the access_db feature and add: 2748 2749 Connect:10.1 OK 2750 Connect:127.0.0.1 RELAY 2751 2752to the access map, where 10.1 is your local network. You may 2753want to use "RELAY" instead of "OK" to allow also relaying 2754instead of just disabling the DNS lookups in the blacklists. 2755 2756 2757The features described above make use of the check_relay, check_mail, 2758and check_rcpt rulesets. Note that check_relay checks the SMTP 2759client hostname and IP address when the connection is made to your 2760server. It does not check if a mail message is being relayed to 2761another server. That check is done in check_rcpt. If you wish to 2762include your own checks, you can put your checks in the rulesets 2763Local_check_relay, Local_check_mail, and Local_check_rcpt. For 2764example if you wanted to block senders with all numeric usernames 2765(i.e. 2312343@bigisp.com), you would use Local_check_mail and the 2766regex map: 2767 2768 LOCAL_CONFIG 2769 Kallnumbers regex -a@MATCH ^[0-9]+$ 2770 2771 LOCAL_RULESETS 2772 SLocal_check_mail 2773 # check address against various regex checks 2774 R$* $: $>Parse0 $>3 $1 2775 R$+ < @ bigisp.com. > $* $: $(allnumbers $1 $) 2776 R@MATCH $#error $: 553 Header Error 2777 2778These rules are called with the original arguments of the corresponding 2779check_* ruleset. If the local ruleset returns $#OK, no further checking 2780is done by the features described above and the mail is accepted. If 2781the local ruleset resolves to a mailer (such as $#error or $#discard), 2782the appropriate action is taken. Other results starting with $# are 2783interpreted by sendmail and may lead to unspecified behavior. Note: do 2784NOT create a mailer with the name OK. Return values that do not start 2785with $# are ignored, i.e., normal processing continues. 2786 2787Delay all checks 2788---------------- 2789 2790By using FEATURE(`delay_checks') the rulesets check_mail and check_relay 2791will not be called when a client connects or issues a MAIL command, 2792respectively. Instead, those rulesets will be called by the check_rcpt 2793ruleset; they will be skipped if a sender has been authenticated using 2794a "trusted" mechanism, i.e., one that is defined via TRUST_AUTH_MECH(). 2795If check_mail returns an error then the RCPT TO command will be rejected 2796with that error. If it returns some other result starting with $# then 2797check_relay will be skipped. If the sender address (or a part of it) is 2798listed in the access map and it has a RHS of OK or RELAY, then check_relay 2799will be skipped. This has an interesting side effect: if your domain is 2800my.domain and you have 2801 2802 my.domain RELAY 2803 2804in the access map, then any e-mail with a sender address of 2805<user@my.domain> will not be rejected by check_relay even though 2806it would match the hostname or IP address. This allows spammers 2807to get around DNS based blacklist by faking the sender address. To 2808avoid this problem you have to use tagged entries: 2809 2810 To:my.domain RELAY 2811 Connect:my.domain RELAY 2812 2813if you need those entries at all (class {R} may take care of them). 2814 2815FEATURE(`delay_checks') can take an optional argument: 2816 2817 FEATURE(`delay_checks', `friend') 2818 enables spamfriend test 2819 FEATURE(`delay_checks', `hater') 2820 enables spamhater test 2821 2822If such an argument is given, the recipient will be looked up in the 2823access map (using the tag Spam:). If the argument is `friend', then 2824the default behavior is to apply the other rulesets and make a SPAM 2825friend the exception. The rulesets check_mail and check_relay will be 2826skipped only if the recipient address is found and has RHS FRIEND. If 2827the argument is `hater', then the default behavior is to skip the rulesets 2828check_mail and check_relay and make a SPAM hater the exception. The 2829other two rulesets will be applied only if the recipient address is 2830found and has RHS HATER. 2831 2832This allows for simple exceptions from the tests, e.g., by activating 2833the friend option and having 2834 2835 Spam:abuse@ FRIEND 2836 2837in the access map, mail to abuse@localdomain will get through (where 2838"localdomain" is any domain in class {w}). It is also possible to 2839specify a full address or an address with +detail: 2840 2841 Spam:abuse@my.domain FRIEND 2842 Spam:me+abuse@ FRIEND 2843 Spam:spam.domain FRIEND 2844 2845Note: The required tag has been changed in 8.12 from To: to Spam:. 2846This change is incompatible to previous versions. However, you can 2847(for now) simply add the new entries to the access map, the old 2848ones will be ignored. As soon as you removed the old entries from 2849the access map, specify a third parameter (`n') to this feature and 2850the backward compatibility rules will not be in the generated .cf 2851file. 2852 2853Header Checks 2854------------- 2855 2856You can also reject mail on the basis of the contents of headers. 2857This is done by adding a ruleset call to the 'H' header definition command 2858in sendmail.cf. For example, this can be used to check the validity of 2859a Message-ID: header: 2860 2861 LOCAL_CONFIG 2862 HMessage-Id: $>CheckMessageId 2863 2864 LOCAL_RULESETS 2865 SCheckMessageId 2866 R< $+ @ $+ > $@ OK 2867 R$* $#error $: 553 Header Error 2868 2869The alternative format: 2870 2871 HSubject: $>+CheckSubject 2872 2873that is, $>+ instead of $>, gives the full Subject: header including 2874comments to the ruleset (comments in parentheses () are stripped 2875by default). 2876 2877A default ruleset for headers which don't have a specific ruleset 2878defined for them can be given by: 2879 2880 H*: $>CheckHdr 2881 2882Notice: 28831. All rules act on tokens as explained in doc/op/op.{me,ps,txt}. 2884That may cause problems with simple header checks due to the 2885tokenization. It might be simpler to use a regex map and apply it 2886to $&{currHeader}. 28872. There are no default rulesets coming with this distribution of 2888sendmail. You can write your own, can search the WWW for examples, 2889or take a look at cf/cf/knecht.mc. 28903. When using a default ruleset for headers, the name of the header 2891currently being checked can be found in the $&{hdr_name} macro. 2892 2893After all of the headers are read, the check_eoh ruleset will be called for 2894any final header-related checks. The ruleset is called with the number of 2895headers and the size of all of the headers in bytes separated by $|. One 2896example usage is to reject messages which do not have a Message-Id: 2897header. However, the Message-Id: header is *NOT* a required header and is 2898not a guaranteed spam indicator. This ruleset is an example and should 2899probably not be used in production. 2900 2901 LOCAL_CONFIG 2902 Kstorage macro 2903 HMessage-Id: $>CheckMessageId 2904 2905 LOCAL_RULESETS 2906 SCheckMessageId 2907 # Record the presence of the header 2908 R$* $: $(storage {MessageIdCheck} $@ OK $) $1 2909 R< $+ @ $+ > $@ OK 2910 R$* $#error $: 553 Header Error 2911 2912 Scheck_eoh 2913 # Check the macro 2914 R$* $: < $&{MessageIdCheck} > 2915 # Clear the macro for the next message 2916 R$* $: $(storage {MessageIdCheck} $) $1 2917 # Has a Message-Id: header 2918 R< $+ > $@ OK 2919 # Allow missing Message-Id: from local mail 2920 R$* $: < $&{client_name} > 2921 R< > $@ OK 2922 R< $=w > $@ OK 2923 # Otherwise, reject the mail 2924 R$* $#error $: 553 Header Error 2925 2926 2927+--------------------+ 2928| CONNECTION CONTROL | 2929+--------------------+ 2930 2931The features ratecontrol and conncontrol allow to establish connection 2932limits per client IP address or net. These features can limit the 2933rate of connections (connections per time unit) or the number of 2934incoming SMTP connections, respectively. If enabled, appropriate 2935rulesets are called at the end of check_relay, i.e., after DNS 2936blacklists and generic access_db operations. The features require 2937FEATURE(`access_db') to be listed earlier in the mc file. 2938 2939Note: FEATURE(`delay_checks') delays those connection control checks 2940after a recipient address has been received, hence making these 2941connection control features less useful. To run the checks as early 2942as possible, specify the parameter `nodelay', e.g., 2943 2944 FEATURE(`ratecontrol', `nodelay') 2945 2946In that case, FEATURE(`delay_checks') has no effect on connection 2947control (and it must be specified earlier in the mc file). 2948 2949An optional second argument `terminate' specifies whether the 2950rulesets should return the error code 421 which will cause 2951sendmail to terminate the session with that error if it is 2952returned from check_relay, i.e., not delayed as explained in 2953the previous paragraph. Example: 2954 2955 FEATURE(`ratecontrol', `nodelay', `terminate') 2956 2957 2958+----------+ 2959| STARTTLS | 2960+----------+ 2961 2962In this text, cert will be used as an abbreviation for X.509 certificate, 2963DN (CN) is the distinguished (common) name of a cert, and CA is a 2964certification authority, which signs (issues) certs. 2965 2966For STARTTLS to be offered by sendmail you need to set at least 2967these variables (the file names and paths are just examples): 2968 2969 define(`confCACERT_PATH', `/etc/mail/certs/') 2970 define(`confCACERT', `/etc/mail/certs/CA.cert.pem') 2971 define(`confSERVER_CERT', `/etc/mail/certs/my.cert.pem') 2972 define(`confSERVER_KEY', `/etc/mail/certs/my.key.pem') 2973 2974On systems which do not have the compile flag HASURANDOM set (see 2975sendmail/README) you also must set confRAND_FILE. 2976 2977See doc/op/op.{me,ps,txt} for more information about these options, 2978especially the sections ``Certificates for STARTTLS'' and ``PRNG for 2979STARTTLS''. 2980 2981Macros related to STARTTLS are: 2982 2983${cert_issuer} holds the DN of the CA (the cert issuer). 2984${cert_subject} holds the DN of the cert (called the cert subject). 2985${cn_issuer} holds the CN of the CA (the cert issuer). 2986${cn_subject} holds the CN of the cert (called the cert subject). 2987${tls_version} the TLS/SSL version used for the connection, e.g., TLSv1, 2988 TLSv1/SSLv3, SSLv3, SSLv2. 2989${cipher} the cipher used for the connection, e.g., EDH-DSS-DES-CBC3-SHA, 2990 EDH-RSA-DES-CBC-SHA, DES-CBC-MD5, DES-CBC3-SHA. 2991${cipher_bits} the keylength (in bits) of the symmetric encryption algorithm 2992 used for the connection. 2993${verify} holds the result of the verification of the presented cert. 2994 Possible values are: 2995 OK verification succeeded. 2996 NO no cert presented. 2997 NOT no cert requested. 2998 FAIL cert presented but could not be verified, 2999 e.g., the cert of the signing CA is missing. 3000 NONE STARTTLS has not been performed. 3001 TEMP temporary error occurred. 3002 PROTOCOL protocol error occurred (SMTP level). 3003 SOFTWARE STARTTLS handshake failed. 3004${server_name} the name of the server of the current outgoing SMTP 3005 connection. 3006${server_addr} the address of the server of the current outgoing SMTP 3007 connection. 3008 3009Relaying 3010-------- 3011 3012SMTP STARTTLS can allow relaying for remote SMTP clients which have 3013successfully authenticated themselves. If the verification of the cert 3014failed (${verify} != OK), relaying is subject to the usual rules. 3015Otherwise the DN of the issuer is looked up in the access map using the 3016tag CERTISSUER. If the resulting value is RELAY, relaying is allowed. 3017If it is SUBJECT, the DN of the cert subject is looked up next in the 3018access map using the tag CERTSUBJECT. If the value is RELAY, relaying 3019is allowed. 3020 3021To make things a bit more flexible (or complicated), the values for 3022${cert_issuer} and ${cert_subject} can be optionally modified by regular 3023expressions defined in the m4 variables _CERT_REGEX_ISSUER_ and 3024_CERT_REGEX_SUBJECT_, respectively. To avoid problems with those macros in 3025rulesets and map lookups, they are modified as follows: each non-printable 3026character and the characters '<', '>', '(', ')', '"', '+', ' ' are replaced 3027by their HEX value with a leading '+'. For example: 3028 3029/C=US/ST=California/O=endmail.org/OU=private/CN=Darth Mail (Cert)/Email= 3030darth+cert@endmail.org 3031 3032is encoded as: 3033 3034/C=US/ST=California/O=endmail.org/OU=private/CN= 3035Darth+20Mail+20+28Cert+29/Email=darth+2Bcert@endmail.org 3036 3037(line breaks have been inserted for readability). 3038 3039The macros which are subject to this encoding are ${cert_subject}, 3040${cert_issuer}, ${cn_subject}, and ${cn_issuer}. 3041 3042Examples: 3043 3044To allow relaying for everyone who can present a cert signed by 3045 3046/C=US/ST=California/O=endmail.org/OU=private/CN= 3047Darth+20Mail+20+28Cert+29/Email=darth+2Bcert@endmail.org 3048 3049simply use: 3050 3051CertIssuer:/C=US/ST=California/O=endmail.org/OU=private/CN= 3052Darth+20Mail+20+28Cert+29/Email=darth+2Bcert@endmail.org RELAY 3053 3054To allow relaying only for a subset of machines that have a cert signed by 3055 3056/C=US/ST=California/O=endmail.org/OU=private/CN= 3057Darth+20Mail+20+28Cert+29/Email=darth+2Bcert@endmail.org 3058 3059use: 3060 3061CertIssuer:/C=US/ST=California/O=endmail.org/OU=private/CN= 3062Darth+20Mail+20+28Cert+29/Email=darth+2Bcert@endmail.org SUBJECT 3063CertSubject:/C=US/ST=California/O=endmail.org/OU=private/CN= 3064DeathStar/Email=deathstar@endmail.org RELAY 3065 3066Notes: 3067- line breaks have been inserted after "CN=" for readability, 3068 each tagged entry must be one (long) line in the access map. 3069- if OpenSSL 0.9.7 or newer is used then the "Email=" part of a DN 3070 is replaced by "emailAddress=". 3071 3072Of course it is also possible to write a simple ruleset that allows 3073relaying for everyone who can present a cert that can be verified, e.g., 3074 3075LOCAL_RULESETS 3076SLocal_check_rcpt 3077R$* $: $&{verify} 3078ROK $# OK 3079 3080Allowing Connections 3081-------------------- 3082 3083The rulesets tls_server, tls_client, and tls_rcpt are used to decide whether 3084an SMTP connection is accepted (or should continue). 3085 3086tls_server is called when sendmail acts as client after a STARTTLS command 3087(should) have been issued. The parameter is the value of ${verify}. 3088 3089tls_client is called when sendmail acts as server, after a STARTTLS command 3090has been issued, and from check_mail. The parameter is the value of 3091${verify} and STARTTLS or MAIL, respectively. 3092 3093Both rulesets behave the same. If no access map is in use, the connection 3094will be accepted unless ${verify} is SOFTWARE, in which case the connection 3095is always aborted. For tls_server/tls_client, ${client_name}/${server_name} 3096is looked up in the access map using the tag TLS_Srv/TLS_Clt, which is done 3097with the ruleset LookUpDomain. If no entry is found, ${client_addr} 3098(${server_addr}) is looked up in the access map (same tag, ruleset 3099LookUpAddr). If this doesn't result in an entry either, just the tag is 3100looked up in the access map (included the trailing colon). Notice: 3101requiring that e-mail is sent to a server only encrypted, e.g., via 3102 3103TLS_Srv:secure.domain ENCR:112 3104 3105doesn't necessarily mean that e-mail sent to that domain is encrypted. 3106If the domain has multiple MX servers, e.g., 3107 3108secure.domain. IN MX 10 mail.secure.domain. 3109secure.domain. IN MX 50 mail.other.domain. 3110 3111then mail to user@secure.domain may go unencrypted to mail.other.domain. 3112tls_rcpt can be used to address this problem. 3113 3114tls_rcpt is called before a RCPT TO: command is sent. The parameter is the 3115current recipient. This ruleset is only defined if FEATURE(`access_db') 3116is selected. A recipient address user@domain is looked up in the access 3117map in four formats: TLS_Rcpt:user@domain, TLS_Rcpt:user@, TLS_Rcpt:domain, 3118and TLS_Rcpt:; the first match is taken. 3119 3120The result of the lookups is then used to call the ruleset TLS_connection, 3121which checks the requirement specified by the RHS in the access map against 3122the actual parameters of the current TLS connection, esp. ${verify} and 3123${cipher_bits}. Legal RHSs in the access map are: 3124 3125VERIFY verification must have succeeded 3126VERIFY:bits verification must have succeeded and ${cipher_bits} must 3127 be greater than or equal bits. 3128ENCR:bits ${cipher_bits} must be greater than or equal bits. 3129 3130The RHS can optionally be prefixed by TEMP+ or PERM+ to select a temporary 3131or permanent error. The default is a temporary error code (403 4.7.0) 3132unless the macro TLS_PERM_ERR is set during generation of the .cf file. 3133 3134If a certain level of encryption is required, then it might also be 3135possible that this level is provided by the security layer from a SASL 3136algorithm, e.g., DIGEST-MD5. 3137 3138Furthermore, there can be a list of extensions added. Such a list 3139starts with '+' and the items are separated by '++'. Allowed 3140extensions are: 3141 3142CN:name name must match ${cn_subject} 3143CN ${server_name} must match ${cn_subject} 3144CS:name name must match ${cert_subject} 3145CI:name name must match ${cert_issuer} 3146 3147Example: e-mail sent to secure.example.com should only use an encrypted 3148connection. E-mail received from hosts within the laptop.example.com domain 3149should only be accepted if they have been authenticated. The host which 3150receives e-mail for darth@endmail.org must present a cert that uses the 3151CN smtp.endmail.org. 3152 3153TLS_Srv:secure.example.com ENCR:112 3154TLS_Clt:laptop.example.com PERM+VERIFY:112 3155TLS_Rcpt:darth@endmail.org ENCR:112+CN:smtp.endmail.org 3156 3157 3158Disabling STARTTLS And Setting SMTP Server Features 3159--------------------------------------------------- 3160 3161By default STARTTLS is used whenever possible. However, there are 3162some broken MTAs that don't properly implement STARTTLS. To be able 3163to send to (or receive from) those MTAs, the ruleset try_tls 3164(srv_features) can be used that work together with the access map. 3165Entries for the access map must be tagged with Try_TLS (Srv_Features) 3166and refer to the hostname or IP address of the connecting system. 3167A default case can be specified by using just the tag. For example, 3168the following entries in the access map: 3169 3170 Try_TLS:broken.server NO 3171 Srv_Features:my.domain v 3172 Srv_Features: V 3173 3174will turn off STARTTLS when sending to broken.server (or any host 3175in that domain), and request a client certificate during the TLS 3176handshake only for hosts in my.domain. The valid entries on the RHS 3177for Srv_Features are listed in the Sendmail Installation and 3178Operations Guide. 3179 3180 3181Received: Header 3182---------------- 3183 3184The Received: header reveals whether STARTTLS has been used. It contains an 3185extra line: 3186 3187(version=${tls_version} cipher=${cipher} bits=${cipher_bits} verify=${verify}) 3188 3189 3190+---------------------+ 3191| SMTP AUTHENTICATION | 3192+---------------------+ 3193 3194The macros ${auth_authen}, ${auth_author}, and ${auth_type} can be 3195used in anti-relay rulesets to allow relaying for those users that 3196authenticated themselves. A very simple example is: 3197 3198SLocal_check_rcpt 3199R$* $: $&{auth_type} 3200R$+ $# OK 3201 3202which checks whether a user has successfully authenticated using 3203any available mechanism. Depending on the setup of the Cyrus SASL 3204library, more sophisticated rulesets might be required, e.g., 3205 3206SLocal_check_rcpt 3207R$* $: $&{auth_type} $| $&{auth_authen} 3208RDIGEST-MD5 $| $+@$=w $# OK 3209 3210to allow relaying for users that authenticated using DIGEST-MD5 3211and have an identity in the local domains. 3212 3213The ruleset trust_auth is used to determine whether a given AUTH= 3214parameter (that is passed to this ruleset) should be trusted. This 3215ruleset may make use of the other ${auth_*} macros. Only if the 3216ruleset resolves to the error mailer, the AUTH= parameter is not 3217trusted. A user supplied ruleset Local_trust_auth can be written 3218to modify the default behavior, which only trust the AUTH= 3219parameter if it is identical to the authenticated user. 3220 3221Per default, relaying is allowed for any user who authenticated 3222via a "trusted" mechanism, i.e., one that is defined via 3223TRUST_AUTH_MECH(`list of mechanisms') 3224For example: 3225TRUST_AUTH_MECH(`KERBEROS_V4 DIGEST-MD5') 3226 3227If the selected mechanism provides a security layer the number of 3228bits used for the key of the symmetric cipher is stored in the 3229macro ${auth_ssf}. 3230 3231Providing SMTP AUTH Data when sendmail acts as Client 3232----------------------------------------------------- 3233 3234If sendmail acts as client, it needs some information how to 3235authenticate against another MTA. This information can be provided 3236by the ruleset authinfo or by the option DefaultAuthInfo. The 3237authinfo ruleset looks up {server_name} using the tag AuthInfo: in 3238the access map. If no entry is found, {server_addr} is looked up 3239in the same way and finally just the tag AuthInfo: to provide 3240default values. Note: searches for domain parts or IP nets are 3241only performed if the access map is used; if the authinfo feature 3242is used then only up to three lookups are performed (two exact 3243matches, one default). 3244 3245Note: If your daemon does client authentication when sending, and 3246if it uses either PLAIN or LOGIN authentication, then you *must* 3247prevent ordinary users from seeing verbose output. Do NOT install 3248sendmail set-user-ID. Use PrivacyOptions to turn off verbose output 3249("goaway" works for this). 3250 3251Notice: the default configuration file causes the option DefaultAuthInfo 3252to fail since the ruleset authinfo is in the .cf file. If you really 3253want to use DefaultAuthInfo (it is deprecated) then you have to 3254remove the ruleset. 3255 3256The RHS for an AuthInfo: entry in the access map should consists of a 3257list of tokens, each of which has the form: "TDstring" (including 3258the quotes). T is a tag which describes the item, D is a delimiter, 3259either ':' for simple text or '=' for a base64 encoded string. 3260Valid values for the tag are: 3261 3262 U user (authorization) id 3263 I authentication id 3264 P password 3265 R realm 3266 M list of mechanisms delimited by spaces 3267 3268Example entries are: 3269 3270AuthInfo:other.dom "U:user" "I:user" "P:secret" "R:other.dom" "M:DIGEST-MD5" 3271AuthInfo:host.more.dom "U:user" "P=c2VjcmV0" 3272 3273User id or authentication id must exist as well as the password. All 3274other entries have default values. If one of user or authentication 3275id is missing, the existing value is used for the missing item. 3276If "R:" is not specified, realm defaults to $j. The list of mechanisms 3277defaults to those specified by AuthMechanisms. 3278 3279Since this map contains sensitive information, either the access 3280map must be unreadable by everyone but root (or the trusted user) 3281or FEATURE(`authinfo') must be used which provides a separate map. 3282Notice: It is not checked whether the map is actually 3283group/world-unreadable, this is left to the user. 3284 3285+--------------------------------+ 3286| ADDING NEW MAILERS OR RULESETS | 3287+--------------------------------+ 3288 3289Sometimes you may need to add entirely new mailers or rulesets. They 3290should be introduced with the constructs MAILER_DEFINITIONS and 3291LOCAL_RULESETS respectively. For example: 3292 3293 MAILER_DEFINITIONS 3294 Mmymailer, ... 3295 ... 3296 3297 LOCAL_RULESETS 3298 Smyruleset 3299 ... 3300 3301Local additions for the rulesets srv_features, try_tls, tls_rcpt, 3302tls_client, and tls_server can be made using LOCAL_SRV_FEATURES, 3303LOCAL_TRY_TLS, LOCAL_TLS_RCPT, LOCAL_TLS_CLIENT, and LOCAL_TLS_SERVER, 3304respectively. For example, to add a local ruleset that decides 3305whether to try STARTTLS in a sendmail client, use: 3306 3307 LOCAL_TRY_TLS 3308 R... 3309 3310Note: you don't need to add a name for the ruleset, it is implicitly 3311defined by using the appropriate macro. 3312 3313 3314+-------------------------+ 3315| ADDING NEW MAIL FILTERS | 3316+-------------------------+ 3317 3318Sendmail supports mail filters to filter incoming SMTP messages according 3319to the "Sendmail Mail Filter API" documentation. These filters can be 3320configured in your mc file using the two commands: 3321 3322 MAIL_FILTER(`name', `equates') 3323 INPUT_MAIL_FILTER(`name', `equates') 3324 3325The first command, MAIL_FILTER(), simply defines a filter with the given 3326name and equates. For example: 3327 3328 MAIL_FILTER(`archive', `S=local:/var/run/archivesock, F=R') 3329 3330This creates the equivalent sendmail.cf entry: 3331 3332 Xarchive, S=local:/var/run/archivesock, F=R 3333 3334The INPUT_MAIL_FILTER() command performs the same actions as MAIL_FILTER 3335but also populates the m4 variable `confINPUT_MAIL_FILTERS' with the name 3336of the filter such that the filter will actually be called by sendmail. 3337 3338For example, the two commands: 3339 3340 INPUT_MAIL_FILTER(`archive', `S=local:/var/run/archivesock, F=R') 3341 INPUT_MAIL_FILTER(`spamcheck', `S=inet:2525@localhost, F=T') 3342 3343are equivalent to the three commands: 3344 3345 MAIL_FILTER(`archive', `S=local:/var/run/archivesock, F=R') 3346 MAIL_FILTER(`spamcheck', `S=inet:2525@localhost, F=T') 3347 define(`confINPUT_MAIL_FILTERS', `archive, spamcheck') 3348 3349In general, INPUT_MAIL_FILTER() should be used unless you need to define 3350more filters than you want to use for `confINPUT_MAIL_FILTERS'. 3351 3352Note that setting `confINPUT_MAIL_FILTERS' after any INPUT_MAIL_FILTER() 3353commands will clear the list created by the prior INPUT_MAIL_FILTER() 3354commands. 3355 3356 3357+-------------------------+ 3358| QUEUE GROUP DEFINITIONS | 3359+-------------------------+ 3360 3361In addition to the queue directory (which is the default queue group 3362called "mqueue"), sendmail can deal with multiple queue groups, which 3363are collections of queue directories with the same behaviour. Queue 3364groups can be defined using the command: 3365 3366 QUEUE_GROUP(`name', `equates') 3367 3368For details about queue groups, please see doc/op/op.{me,ps,txt}. 3369 3370+-------------------------------+ 3371| NON-SMTP BASED CONFIGURATIONS | 3372+-------------------------------+ 3373 3374These configuration files are designed primarily for use by 3375SMTP-based sites. They may not be well tuned for UUCP-only or 3376UUCP-primarily nodes (the latter is defined as a small local net 3377connected to the rest of the world via UUCP). However, there is 3378one hook to handle some special cases. 3379 3380You can define a ``smart host'' that understands a richer address syntax 3381using: 3382 3383 define(`SMART_HOST', `mailer:hostname') 3384 3385In this case, the ``mailer:'' defaults to "relay". Any messages that 3386can't be handled using the usual UUCP rules are passed to this host. 3387 3388If you are on a local SMTP-based net that connects to the outside 3389world via UUCP, you can use LOCAL_NET_CONFIG to add appropriate rules. 3390For example: 3391 3392 define(`SMART_HOST', `uucp-new:uunet') 3393 LOCAL_NET_CONFIG 3394 R$* < @ $* .$m. > $* $#smtp $@ $2.$m. $: $1 < @ $2.$m. > $3 3395 3396This will cause all names that end in your domain name ($m) to be sent 3397via SMTP; anything else will be sent via uucp-new (smart UUCP) to uunet. 3398If you have FEATURE(`nocanonify'), you may need to omit the dots after 3399the $m. If you are running a local DNS inside your domain which is 3400not otherwise connected to the outside world, you probably want to 3401use: 3402 3403 define(`SMART_HOST', `smtp:fire.wall.com') 3404 LOCAL_NET_CONFIG 3405 R$* < @ $* . > $* $#smtp $@ $2. $: $1 < @ $2. > $3 3406 3407That is, send directly only to things you found in your DNS lookup; 3408anything else goes through SMART_HOST. 3409 3410You may need to turn off the anti-spam rules in order to accept 3411UUCP mail with FEATURE(`promiscuous_relay') and 3412FEATURE(`accept_unresolvable_domains'). 3413 3414 3415+-----------+ 3416| WHO AM I? | 3417+-----------+ 3418 3419Normally, the $j macro is automatically defined to be your fully 3420qualified domain name (FQDN). Sendmail does this by getting your 3421host name using gethostname and then calling gethostbyname on the 3422result. For example, in some environments gethostname returns 3423only the root of the host name (such as "foo"); gethostbyname is 3424supposed to return the FQDN ("foo.bar.com"). In some (fairly rare) 3425cases, gethostbyname may fail to return the FQDN. In this case 3426you MUST define confDOMAIN_NAME to be your fully qualified domain 3427name. This is usually done using: 3428 3429 Dmbar.com 3430 define(`confDOMAIN_NAME', `$w.$m')dnl 3431 3432 3433+-----------------------------------+ 3434| ACCEPTING MAIL FOR MULTIPLE NAMES | 3435+-----------------------------------+ 3436 3437If your host is known by several different names, you need to augment 3438class {w}. This is a list of names by which your host is known, and 3439anything sent to an address using a host name in this list will be 3440treated as local mail. You can do this in two ways: either create the 3441file /etc/mail/local-host-names containing a list of your aliases (one per 3442line), and use ``FEATURE(`use_cw_file')'' in the .mc file, or add 3443``LOCAL_DOMAIN(`alias.host.name')''. Be sure you use the fully-qualified 3444name of the host, rather than a short name. 3445 3446If you want to have different address in different domains, take 3447a look at the virtusertable feature, which is also explained at 3448http://www.sendmail.org/virtual-hosting.html 3449 3450 3451+--------------------+ 3452| USING MAILERTABLES | 3453+--------------------+ 3454 3455To use FEATURE(`mailertable'), you will have to create an external 3456database containing the routing information for various domains. 3457For example, a mailertable file in text format might be: 3458 3459 .my.domain xnet:%1.my.domain 3460 uuhost1.my.domain uucp-new:uuhost1 3461 .bitnet smtp:relay.bit.net 3462 3463This should normally be stored in /etc/mail/mailertable. The actual 3464database version of the mailertable is built using: 3465 3466 makemap hash /etc/mail/mailertable < /etc/mail/mailertable 3467 3468The semantics are simple. Any LHS entry that does not begin with 3469a dot matches the full host name indicated. LHS entries beginning 3470with a dot match anything ending with that domain name (including 3471the leading dot) -- that is, they can be thought of as having a 3472leading ".+" regular expression pattern for a non-empty sequence of 3473characters. Matching is done in order of most-to-least qualified 3474-- for example, even though ".my.domain" is listed first in the 3475above example, an entry of "uuhost1.my.domain" will match the second 3476entry since it is more explicit. Note: e-mail to "user@my.domain" 3477does not match any entry in the above table. You need to have 3478something like: 3479 3480 my.domain esmtp:host.my.domain 3481 3482The RHS should always be a "mailer:host" pair. The mailer is the 3483configuration name of a mailer (that is, an M line in the 3484sendmail.cf file). The "host" will be the hostname passed to 3485that mailer. In domain-based matches (that is, those with leading 3486dots) the "%1" may be used to interpolate the wildcarded part of 3487the host name. For example, the first line above sends everything 3488addressed to "anything.my.domain" to that same host name, but using 3489the (presumably experimental) xnet mailer. 3490 3491In some cases you may want to temporarily turn off MX records, 3492particularly on gateways. For example, you may want to MX 3493everything in a domain to one machine that then forwards it 3494directly. To do this, you might use the DNS configuration: 3495 3496 *.domain. IN MX 0 relay.machine 3497 3498and on relay.machine use the mailertable: 3499 3500 .domain smtp:[gateway.domain] 3501 3502The [square brackets] turn off MX records for this host only. 3503If you didn't do this, the mailertable would use the MX record 3504again, which would give you an MX loop. Note that the use of 3505wildcard MX records is almost always a bad idea. Please avoid 3506using them if possible. 3507 3508 3509+--------------------------------+ 3510| USING USERDB TO MAP FULL NAMES | 3511+--------------------------------+ 3512 3513The user database was not originally intended for mapping full names 3514to login names (e.g., Eric.Allman => eric), but some people are using 3515it that way. (it is recommended that you set up aliases for this 3516purpose instead -- since you can specify multiple alias files, this 3517is fairly easy.) The intent was to locate the default maildrop at 3518a site, but allow you to override this by sending to a specific host. 3519 3520If you decide to set up the user database in this fashion, it is 3521imperative that you not use FEATURE(`stickyhost') -- otherwise, 3522e-mail sent to Full.Name@local.host.name will be rejected. 3523 3524To build the internal form of the user database, use: 3525 3526 makemap btree /etc/mail/userdb < /etc/mail/userdb.txt 3527 3528As a general rule, it is an extremely bad idea to using full names 3529as e-mail addresses, since they are not in any sense unique. For 3530example, the UNIX software-development community has at least two 3531well-known Peter Deutsches, and at one time Bell Labs had two 3532Stephen R. Bournes with offices along the same hallway. Which one 3533will be forced to suffer the indignity of being Stephen_R_Bourne_2? 3534The less famous of the two, or the one that was hired later? 3535 3536Finger should handle full names (and be fuzzy). Mail should use 3537handles, and not be fuzzy. 3538 3539 3540+--------------------------------+ 3541| MISCELLANEOUS SPECIAL FEATURES | 3542+--------------------------------+ 3543 3544Plussed users 3545 Sometimes it is convenient to merge configuration on a 3546 centralized mail machine, for example, to forward all 3547 root mail to a mail server. In this case it might be 3548 useful to be able to treat the root addresses as a class 3549 of addresses with subtle differences. You can do this 3550 using plussed users. For example, a client might include 3551 the alias: 3552 3553 root: root+client1@server 3554 3555 On the server, this will match an alias for "root+client1". 3556 If that is not found, the alias "root+*" will be tried, 3557 then "root". 3558 3559 3560+----------------+ 3561| SECURITY NOTES | 3562+----------------+ 3563 3564A lot of sendmail security comes down to you. Sendmail 8 is much 3565more careful about checking for security problems than previous 3566versions, but there are some things that you still need to watch 3567for. In particular: 3568 3569* Make sure the aliases file is not writable except by trusted 3570 system personnel. This includes both the text and database 3571 version. 3572 3573* Make sure that other files that sendmail reads, such as the 3574 mailertable, are only writable by trusted system personnel. 3575 3576* The queue directory should not be world writable PARTICULARLY 3577 if your system allows "file giveaways" (that is, if a non-root 3578 user can chown any file they own to any other user). 3579 3580* If your system allows file giveaways, DO NOT create a publically 3581 writable directory for forward files. This will allow anyone 3582 to steal anyone else's e-mail. Instead, create a script that 3583 copies the .forward file from users' home directories once a 3584 night (if you want the non-NFS-mounted forward directory). 3585 3586* If your system allows file giveaways, you'll find that 3587 sendmail is much less trusting of :include: files -- in 3588 particular, you'll have to have /SENDMAIL/ANY/SHELL/ in 3589 /etc/shells before they will be trusted (that is, before 3590 files and programs listed in them will be honored). 3591 3592In general, file giveaways are a mistake -- if you can turn them 3593off, do so. 3594 3595 3596+--------------------------------+ 3597| TWEAKING CONFIGURATION OPTIONS | 3598+--------------------------------+ 3599 3600There are a large number of configuration options that don't normally 3601need to be changed. However, if you feel you need to tweak them, 3602you can define the following M4 variables. Note that some of these 3603variables require formats that are defined in RFC 2821 or RFC 2822. 3604Before changing them you need to make sure you do not violate those 3605(and other relevant) RFCs. 3606 3607This list is shown in four columns: the name you define, the default 3608value for that definition, the option or macro that is affected 3609(either Ox for an option or Dx for a macro), and a brief description. 3610Greater detail of the semantics can be found in the Installation 3611and Operations Guide. 3612 3613Some options are likely to be deprecated in future versions -- that is, 3614the option is only included to provide back-compatibility. These are 3615marked with "*". 3616 3617Remember that these options are M4 variables, and hence may need to 3618be quoted. In particular, arguments with commas will usually have to 3619be ``double quoted, like this phrase'' to avoid having the comma 3620confuse things. This is common for alias file definitions and for 3621the read timeout. 3622 3623M4 Variable Name Configuration [Default] & Description 3624================ ============= ======================= 3625confMAILER_NAME $n macro [MAILER-DAEMON] The sender name used 3626 for internally generated outgoing 3627 messages. 3628confDOMAIN_NAME $j macro If defined, sets $j. This should 3629 only be done if your system cannot 3630 determine your local domain name, 3631 and then it should be set to 3632 $w.Foo.COM, where Foo.COM is your 3633 domain name. 3634confCF_VERSION $Z macro If defined, this is appended to the 3635 configuration version name. 3636confLDAP_CLUSTER ${sendmailMTACluster} macro 3637 If defined, this is the LDAP 3638 cluster to use for LDAP searches 3639 as described above in ``USING LDAP 3640 FOR ALIASES, MAPS, AND CLASSES''. 3641confFROM_HEADER From: [$?x$x <$g>$|$g$.] The format of an 3642 internally generated From: address. 3643confRECEIVED_HEADER Received: 3644 [$?sfrom $s $.$?_($?s$|from $.$_) 3645 $.$?{auth_type}(authenticated) 3646 $.by $j ($v/$Z)$?r with $r$. id $i$?u 3647 for $u; $|; 3648 $.$b] 3649 The format of the Received: header 3650 in messages passed through this host. 3651 It is unwise to try to change this. 3652confMESSAGEID_HEADER Message-Id: [<$t.$i@$j>] The format of an 3653 internally generated Message-Id: 3654 header. 3655confCW_FILE Fw class [/etc/mail/local-host-names] Name 3656 of file used to get the local 3657 additions to class {w} (local host 3658 names). 3659confCT_FILE Ft class [/etc/mail/trusted-users] Name of 3660 file used to get the local additions 3661 to class {t} (trusted users). 3662confCR_FILE FR class [/etc/mail/relay-domains] Name of 3663 file used to get the local additions 3664 to class {R} (hosts allowed to relay). 3665confTRUSTED_USERS Ct class [no default] Names of users to add to 3666 the list of trusted users. This list 3667 always includes root, uucp, and daemon. 3668 See also FEATURE(`use_ct_file'). 3669confTRUSTED_USER TrustedUser [no default] Trusted user for file 3670 ownership and starting the daemon. 3671 Not to be confused with 3672 confTRUSTED_USERS (see above). 3673confSMTP_MAILER - [esmtp] The mailer name used when 3674 SMTP connectivity is required. 3675 One of "smtp", "smtp8", 3676 "esmtp", or "dsmtp". 3677confUUCP_MAILER - [uucp-old] The mailer to be used by 3678 default for bang-format recipient 3679 addresses. See also discussion of 3680 class {U}, class {Y}, and class {Z} 3681 in the MAILER(`uucp') section. 3682confLOCAL_MAILER - [local] The mailer name used when 3683 local connectivity is required. 3684 Almost always "local". 3685confRELAY_MAILER - [relay] The default mailer name used 3686 for relaying any mail (e.g., to a 3687 BITNET_RELAY, a SMART_HOST, or 3688 whatever). This can reasonably be 3689 "uucp-new" if you are on a 3690 UUCP-connected site. 3691confSEVEN_BIT_INPUT SevenBitInput [False] Force input to seven bits? 3692confEIGHT_BIT_HANDLING EightBitMode [pass8] 8-bit data handling 3693confALIAS_WAIT AliasWait [10m] Time to wait for alias file 3694 rebuild until you get bored and 3695 decide that the apparently pending 3696 rebuild failed. 3697confMIN_FREE_BLOCKS MinFreeBlocks [100] Minimum number of free blocks on 3698 queue filesystem to accept SMTP mail. 3699 (Prior to 8.7 this was minfree/maxsize, 3700 where minfree was the number of free 3701 blocks and maxsize was the maximum 3702 message size. Use confMAX_MESSAGE_SIZE 3703 for the second value now.) 3704confMAX_MESSAGE_SIZE MaxMessageSize [infinite] The maximum size of messages 3705 that will be accepted (in bytes). 3706confBLANK_SUB BlankSub [.] Blank (space) substitution 3707 character. 3708confCON_EXPENSIVE HoldExpensive [False] Avoid connecting immediately 3709 to mailers marked expensive. 3710confCHECKPOINT_INTERVAL CheckpointInterval 3711 [10] Checkpoint queue files every N 3712 recipients. 3713confDELIVERY_MODE DeliveryMode [background] Default delivery mode. 3714confERROR_MODE ErrorMode [print] Error message mode. 3715confERROR_MESSAGE ErrorHeader [undefined] Error message header/file. 3716confSAVE_FROM_LINES SaveFromLine Save extra leading From_ lines. 3717confTEMP_FILE_MODE TempFileMode [0600] Temporary file mode. 3718confMATCH_GECOS MatchGECOS [False] Match GECOS field. 3719confMAX_HOP MaxHopCount [25] Maximum hop count. 3720confIGNORE_DOTS* IgnoreDots [False; always False in -bs or -bd 3721 mode] Ignore dot as terminator for 3722 incoming messages? 3723confBIND_OPTS ResolverOptions [undefined] Default options for DNS 3724 resolver. 3725confMIME_FORMAT_ERRORS* SendMimeErrors [True] Send error messages as MIME- 3726 encapsulated messages per RFC 1344. 3727confFORWARD_PATH ForwardPath [$z/.forward.$w:$z/.forward] 3728 The colon-separated list of places to 3729 search for .forward files. N.B.: see 3730 the Security Notes section. 3731confMCI_CACHE_SIZE ConnectionCacheSize 3732 [2] Size of open connection cache. 3733confMCI_CACHE_TIMEOUT ConnectionCacheTimeout 3734 [5m] Open connection cache timeout. 3735confHOST_STATUS_DIRECTORY HostStatusDirectory 3736 [undefined] If set, host status is kept 3737 on disk between sendmail runs in the 3738 named directory tree. This need not be 3739 a full pathname, in which case it is 3740 interpreted relative to the queue 3741 directory. 3742confSINGLE_THREAD_DELIVERY SingleThreadDelivery 3743 [False] If this option and the 3744 HostStatusDirectory option are both 3745 set, single thread deliveries to other 3746 hosts. That is, don't allow any two 3747 sendmails on this host to connect 3748 simultaneously to any other single 3749 host. This can slow down delivery in 3750 some cases, in particular since a 3751 cached but otherwise idle connection 3752 to a host will prevent other sendmails 3753 from connecting to the other host. 3754confUSE_ERRORS_TO* UseErrorsTo [False] Use the Errors-To: header to 3755 deliver error messages. This should 3756 not be necessary because of general 3757 acceptance of the envelope/header 3758 distinction. 3759confLOG_LEVEL LogLevel [9] Log level. 3760confME_TOO MeToo [True] Include sender in group 3761 expansions. This option is 3762 deprecated and will be removed from 3763 a future version. 3764confCHECK_ALIASES CheckAliases [False] Check RHS of aliases when 3765 running newaliases. Since this does 3766 DNS lookups on every address, it can 3767 slow down the alias rebuild process 3768 considerably on large alias files. 3769confOLD_STYLE_HEADERS* OldStyleHeaders [True] Assume that headers without 3770 special chars are old style. 3771confPRIVACY_FLAGS PrivacyOptions [authwarnings] Privacy flags. 3772confCOPY_ERRORS_TO PostmasterCopy [undefined] Address for additional 3773 copies of all error messages. 3774confQUEUE_FACTOR QueueFactor [600000] Slope of queue-only function. 3775confQUEUE_FILE_MODE QueueFileMode [undefined] Default permissions for 3776 queue files (octal). If not set, 3777 sendmail uses 0600 unless its real 3778 and effective uid are different in 3779 which case it uses 0644. 3780confDONT_PRUNE_ROUTES DontPruneRoutes [False] Don't prune down route-addr 3781 syntax addresses to the minimum 3782 possible. 3783confSAFE_QUEUE* SuperSafe [True] Commit all messages to disk 3784 before forking. 3785confTO_INITIAL Timeout.initial [5m] The timeout waiting for a response 3786 on the initial connect. 3787confTO_CONNECT Timeout.connect [0] The timeout waiting for an initial 3788 connect() to complete. This can only 3789 shorten connection timeouts; the kernel 3790 silently enforces an absolute maximum 3791 (which varies depending on the system). 3792confTO_ICONNECT Timeout.iconnect 3793 [undefined] Like Timeout.connect, but 3794 applies only to the very first attempt 3795 to connect to a host in a message. 3796 This allows a single very fast pass 3797 followed by more careful delivery 3798 attempts in the future. 3799confTO_ACONNECT Timeout.aconnect 3800 [0] The overall timeout waiting for 3801 all connection for a single delivery 3802 attempt to succeed. If 0, no overall 3803 limit is applied. 3804confTO_HELO Timeout.helo [5m] The timeout waiting for a response 3805 to a HELO or EHLO command. 3806confTO_MAIL Timeout.mail [10m] The timeout waiting for a 3807 response to the MAIL command. 3808confTO_RCPT Timeout.rcpt [1h] The timeout waiting for a response 3809 to the RCPT command. 3810confTO_DATAINIT Timeout.datainit 3811 [5m] The timeout waiting for a 354 3812 response from the DATA command. 3813confTO_DATABLOCK Timeout.datablock 3814 [1h] The timeout waiting for a block 3815 during DATA phase. 3816confTO_DATAFINAL Timeout.datafinal 3817 [1h] The timeout waiting for a response 3818 to the final "." that terminates a 3819 message. 3820confTO_RSET Timeout.rset [5m] The timeout waiting for a response 3821 to the RSET command. 3822confTO_QUIT Timeout.quit [2m] The timeout waiting for a response 3823 to the QUIT command. 3824confTO_MISC Timeout.misc [2m] The timeout waiting for a response 3825 to other SMTP commands. 3826confTO_COMMAND Timeout.command [1h] In server SMTP, the timeout 3827 waiting for a command to be issued. 3828confTO_IDENT Timeout.ident [5s] The timeout waiting for a 3829 response to an IDENT query. 3830confTO_FILEOPEN Timeout.fileopen 3831 [60s] The timeout waiting for a file 3832 (e.g., :include: file) to be opened. 3833confTO_LHLO Timeout.lhlo [2m] The timeout waiting for a response 3834 to an LMTP LHLO command. 3835confTO_AUTH Timeout.auth [10m] The timeout waiting for a 3836 response in an AUTH dialogue. 3837confTO_STARTTLS Timeout.starttls 3838 [1h] The timeout waiting for a 3839 response to an SMTP STARTTLS command. 3840confTO_CONTROL Timeout.control 3841 [2m] The timeout for a complete 3842 control socket transaction to complete. 3843confTO_QUEUERETURN Timeout.queuereturn 3844 [5d] The timeout before a message is 3845 returned as undeliverable. 3846confTO_QUEUERETURN_NORMAL 3847 Timeout.queuereturn.normal 3848 [undefined] As above, for normal 3849 priority messages. 3850confTO_QUEUERETURN_URGENT 3851 Timeout.queuereturn.urgent 3852 [undefined] As above, for urgent 3853 priority messages. 3854confTO_QUEUERETURN_NONURGENT 3855 Timeout.queuereturn.non-urgent 3856 [undefined] As above, for non-urgent 3857 (low) priority messages. 3858confTO_QUEUERETURN_DSN 3859 Timeout.queuereturn.dsn 3860 [undefined] As above, for delivery 3861 status notification messages. 3862confTO_QUEUEWARN Timeout.queuewarn 3863 [4h] The timeout before a warning 3864 message is sent to the sender telling 3865 them that the message has been 3866 deferred. 3867confTO_QUEUEWARN_NORMAL Timeout.queuewarn.normal 3868 [undefined] As above, for normal 3869 priority messages. 3870confTO_QUEUEWARN_URGENT Timeout.queuewarn.urgent 3871 [undefined] As above, for urgent 3872 priority messages. 3873confTO_QUEUEWARN_NONURGENT 3874 Timeout.queuewarn.non-urgent 3875 [undefined] As above, for non-urgent 3876 (low) priority messages. 3877confTO_QUEUEWARN_DSN 3878 Timeout.queuewarn.dsn 3879 [undefined] As above, for delivery 3880 status notification messages. 3881confTO_HOSTSTATUS Timeout.hoststatus 3882 [30m] How long information about host 3883 statuses will be maintained before it 3884 is considered stale and the host should 3885 be retried. This applies both within 3886 a single queue run and to persistent 3887 information (see below). 3888confTO_RESOLVER_RETRANS Timeout.resolver.retrans 3889 [varies] Sets the resolver's 3890 retransmission time interval (in 3891 seconds). Sets both 3892 Timeout.resolver.retrans.first and 3893 Timeout.resolver.retrans.normal. 3894confTO_RESOLVER_RETRANS_FIRST Timeout.resolver.retrans.first 3895 [varies] Sets the resolver's 3896 retransmission time interval (in 3897 seconds) for the first attempt to 3898 deliver a message. 3899confTO_RESOLVER_RETRANS_NORMAL Timeout.resolver.retrans.normal 3900 [varies] Sets the resolver's 3901 retransmission time interval (in 3902 seconds) for all resolver lookups 3903 except the first delivery attempt. 3904confTO_RESOLVER_RETRY Timeout.resolver.retry 3905 [varies] Sets the number of times 3906 to retransmit a resolver query. 3907 Sets both 3908 Timeout.resolver.retry.first and 3909 Timeout.resolver.retry.normal. 3910confTO_RESOLVER_RETRY_FIRST Timeout.resolver.retry.first 3911 [varies] Sets the number of times 3912 to retransmit a resolver query for 3913 the first attempt to deliver a 3914 message. 3915confTO_RESOLVER_RETRY_NORMAL Timeout.resolver.retry.normal 3916 [varies] Sets the number of times 3917 to retransmit a resolver query for 3918 all resolver lookups except the 3919 first delivery attempt. 3920confTIME_ZONE TimeZoneSpec [USE_SYSTEM] Time zone info -- can be 3921 USE_SYSTEM to use the system's idea, 3922 USE_TZ to use the user's TZ envariable, 3923 or something else to force that value. 3924confDEF_USER_ID DefaultUser [1:1] Default user id. 3925confUSERDB_SPEC UserDatabaseSpec 3926 [undefined] User database 3927 specification. 3928confFALLBACK_MX FallbackMXhost [undefined] Fallback MX host. 3929confFALLBACK_SMARTHOST FallbackSmartHost 3930 [undefined] Fallback smart host. 3931confTRY_NULL_MX_LIST TryNullMXList [False] If this host is the best MX 3932 for a host and other arrangements 3933 haven't been made, try connecting 3934 to the host directly; normally this 3935 would be a config error. 3936confQUEUE_LA QueueLA [varies] Load average at which 3937 queue-only function kicks in. 3938 Default values is (8 * numproc) 3939 where numproc is the number of 3940 processors online (if that can be 3941 determined). 3942confREFUSE_LA RefuseLA [varies] Load average at which 3943 incoming SMTP connections are 3944 refused. Default values is (12 * 3945 numproc) where numproc is the 3946 number of processors online (if 3947 that can be determined). 3948confREJECT_LOG_INTERVAL RejectLogInterval [3h] Log interval when 3949 refusing connections for this long. 3950confDELAY_LA DelayLA [0] Load average at which sendmail 3951 will sleep for one second on most 3952 SMTP commands and before accepting 3953 connections. 0 means no limit. 3954confMAX_ALIAS_RECURSION MaxAliasRecursion 3955 [10] Maximum depth of alias recursion. 3956confMAX_DAEMON_CHILDREN MaxDaemonChildren 3957 [undefined] The maximum number of 3958 children the daemon will permit. After 3959 this number, connections will be 3960 rejected. If not set or <= 0, there is 3961 no limit. 3962confMAX_HEADERS_LENGTH MaxHeadersLength 3963 [32768] Maximum length of the sum 3964 of all headers. 3965confMAX_MIME_HEADER_LENGTH MaxMimeHeaderLength 3966 [undefined] Maximum length of 3967 certain MIME header field values. 3968confCONNECTION_RATE_THROTTLE ConnectionRateThrottle 3969 [undefined] The maximum number of 3970 connections permitted per second per 3971 daemon. After this many connections 3972 are accepted, further connections 3973 will be delayed. If not set or <= 0, 3974 there is no limit. 3975confCONNECTION_RATE_WINDOW_SIZE ConnectionRateWindowSize 3976 [60s] Define the length of the 3977 interval for which the number of 3978 incoming connections is maintained. 3979confWORK_RECIPIENT_FACTOR 3980 RecipientFactor [30000] Cost of each recipient. 3981confSEPARATE_PROC ForkEachJob [False] Run all deliveries in a 3982 separate process. 3983confWORK_CLASS_FACTOR ClassFactor [1800] Priority multiplier for class. 3984confWORK_TIME_FACTOR RetryFactor [90000] Cost of each delivery attempt. 3985confQUEUE_SORT_ORDER QueueSortOrder [Priority] Queue sort algorithm: 3986 Priority, Host, Filename, Random, 3987 Modification, or Time. 3988confMIN_QUEUE_AGE MinQueueAge [0] The minimum amount of time a job 3989 must sit in the queue between queue 3990 runs. This allows you to set the 3991 queue run interval low for better 3992 responsiveness without trying all 3993 jobs in each run. 3994confDEF_CHAR_SET DefaultCharSet [unknown-8bit] When converting 3995 unlabeled 8 bit input to MIME, the 3996 character set to use by default. 3997confSERVICE_SWITCH_FILE ServiceSwitchFile 3998 [/etc/mail/service.switch] The file 3999 to use for the service switch on 4000 systems that do not have a 4001 system-defined switch. 4002confHOSTS_FILE HostsFile [/etc/hosts] The file to use when doing 4003 "file" type access of hosts names. 4004confDIAL_DELAY DialDelay [0s] If a connection fails, wait this 4005 long and try again. Zero means "don't 4006 retry". This is to allow "dial on 4007 demand" connections to have enough time 4008 to complete a connection. 4009confNO_RCPT_ACTION NoRecipientAction 4010 [none] What to do if there are no legal 4011 recipient fields (To:, Cc: or Bcc:) 4012 in the message. Legal values can 4013 be "none" to just leave the 4014 nonconforming message as is, "add-to" 4015 to add a To: header with all the 4016 known recipients (which may expose 4017 blind recipients), "add-apparently-to" 4018 to do the same but use Apparently-To: 4019 instead of To: (strongly discouraged 4020 in accordance with IETF standards), 4021 "add-bcc" to add an empty Bcc: 4022 header, or "add-to-undisclosed" to 4023 add the header 4024 ``To: undisclosed-recipients:;''. 4025confSAFE_FILE_ENV SafeFileEnvironment 4026 [undefined] If set, sendmail will do a 4027 chroot() into this directory before 4028 writing files. 4029confCOLON_OK_IN_ADDR ColonOkInAddr [True unless Configuration Level > 6] 4030 If set, colons are treated as a regular 4031 character in addresses. If not set, 4032 they are treated as the introducer to 4033 the RFC 822 "group" syntax. Colons are 4034 handled properly in route-addrs. This 4035 option defaults on for V5 and lower 4036 configuration files. 4037confMAX_QUEUE_RUN_SIZE MaxQueueRunSize [0] If set, limit the maximum size of 4038 any given queue run to this number of 4039 entries. Essentially, this will stop 4040 reading each queue directory after this 4041 number of entries are reached; it does 4042 _not_ pick the highest priority jobs, 4043 so this should be as large as your 4044 system can tolerate. If not set, there 4045 is no limit. 4046confMAX_QUEUE_CHILDREN MaxQueueChildren 4047 [undefined] Limits the maximum number 4048 of concurrent queue runners active. 4049 This is to keep system resources used 4050 within a reasonable limit. Relates to 4051 Queue Groups and ForkEachJob. 4052confMAX_RUNNERS_PER_QUEUE MaxRunnersPerQueue 4053 [1] Only active when MaxQueueChildren 4054 defined. Controls the maximum number 4055 of queue runners (aka queue children) 4056 active at the same time in a work 4057 group. See also MaxQueueChildren. 4058confDONT_EXPAND_CNAMES DontExpandCnames 4059 [False] If set, $[ ... $] lookups that 4060 do DNS based lookups do not expand 4061 CNAME records. This currently violates 4062 the published standards, but the IETF 4063 seems to be moving toward legalizing 4064 this. For example, if "FTP.Foo.ORG" 4065 is a CNAME for "Cruft.Foo.ORG", then 4066 with this option set a lookup of 4067 "FTP" will return "FTP.Foo.ORG"; if 4068 clear it returns "Cruft.FOO.ORG". N.B. 4069 you may not see any effect until your 4070 downstream neighbors stop doing CNAME 4071 lookups as well. 4072confFROM_LINE UnixFromLine [From $g $d] The From_ line used 4073 when sending to files or programs. 4074confSINGLE_LINE_FROM_HEADER SingleLineFromHeader 4075 [False] From: lines that have 4076 embedded newlines are unwrapped 4077 onto one line. 4078confALLOW_BOGUS_HELO AllowBogusHELO [False] Allow HELO SMTP command that 4079 does not include a host name. 4080confMUST_QUOTE_CHARS MustQuoteChars [.'] Characters to be quoted in a full 4081 name phrase (@,;:\()[] are automatic). 4082confOPERATORS OperatorChars [.:%@!^/[]+] Address operator 4083 characters. 4084confSMTP_LOGIN_MSG SmtpGreetingMessage 4085 [$j Sendmail $v/$Z; $b] 4086 The initial (spontaneous) SMTP 4087 greeting message. The word "ESMTP" 4088 will be inserted between the first and 4089 second words to convince other 4090 sendmails to try to speak ESMTP. 4091confDONT_INIT_GROUPS DontInitGroups [False] If set, the initgroups(3) 4092 routine will never be invoked. You 4093 might want to do this if you are 4094 running NIS and you have a large group 4095 map, since this call does a sequential 4096 scan of the map; in a large site this 4097 can cause your ypserv to run 4098 essentially full time. If you set 4099 this, agents run on behalf of users 4100 will only have their primary 4101 (/etc/passwd) group permissions. 4102confUNSAFE_GROUP_WRITES UnsafeGroupWrites 4103 [True] If set, group-writable 4104 :include: and .forward files are 4105 considered "unsafe", that is, programs 4106 and files cannot be directly referenced 4107 from such files. World-writable files 4108 are always considered unsafe. 4109 Notice: this option is deprecated and 4110 will be removed in future versions; 4111 Set GroupWritableForwardFileSafe 4112 and GroupWritableIncludeFileSafe in 4113 DontBlameSendmail if required. 4114confCONNECT_ONLY_TO ConnectOnlyTo [undefined] override connection 4115 address (for testing). 4116confCONTROL_SOCKET_NAME ControlSocketName 4117 [undefined] Control socket for daemon 4118 management. 4119confDOUBLE_BOUNCE_ADDRESS DoubleBounceAddress 4120 [postmaster] If an error occurs when 4121 sending an error message, send that 4122 "double bounce" error message to this 4123 address. If it expands to an empty 4124 string, double bounces are dropped. 4125confSOFT_BOUNCE SoftBounce [False] If set, issue temporary errors 4126 (4xy) instead of permanent errors 4127 (5xy). This can be useful during 4128 testing of a new configuration to 4129 avoid erroneous bouncing of mails. 4130confDEAD_LETTER_DROP DeadLetterDrop [undefined] Filename to save bounce 4131 messages which could not be returned 4132 to the user or sent to postmaster. 4133 If not set, the queue file will 4134 be renamed. 4135confRRT_IMPLIES_DSN RrtImpliesDsn [False] Return-Receipt-To: header 4136 implies DSN request. 4137confRUN_AS_USER RunAsUser [undefined] If set, become this user 4138 when reading and delivering mail. 4139 Causes all file reads (e.g., .forward 4140 and :include: files) to be done as 4141 this user. Also, all programs will 4142 be run as this user, and all output 4143 files will be written as this user. 4144confMAX_RCPTS_PER_MESSAGE MaxRecipientsPerMessage 4145 [infinite] If set, allow no more than 4146 the specified number of recipients in 4147 an SMTP envelope. Further recipients 4148 receive a 452 error code (i.e., they 4149 are deferred for the next delivery 4150 attempt). 4151confBAD_RCPT_THROTTLE BadRcptThrottle [infinite] If set and the specified 4152 number of recipients in a single SMTP 4153 transaction have been rejected, sleep 4154 for one second after each subsequent 4155 RCPT command in that transaction. 4156confDONT_PROBE_INTERFACES DontProbeInterfaces 4157 [False] If set, sendmail will _not_ 4158 insert the names and addresses of any 4159 local interfaces into class {w} 4160 (list of known "equivalent" addresses). 4161 If you set this, you must also include 4162 some support for these addresses (e.g., 4163 in a mailertable entry) -- otherwise, 4164 mail to addresses in this list will 4165 bounce with a configuration error. 4166 If set to "loopback" (without 4167 quotes), sendmail will skip 4168 loopback interfaces (e.g., "lo0"). 4169confPID_FILE PidFile [system dependent] Location of pid 4170 file. 4171confPROCESS_TITLE_PREFIX ProcessTitlePrefix 4172 [undefined] Prefix string for the 4173 process title shown on 'ps' listings. 4174confDONT_BLAME_SENDMAIL DontBlameSendmail 4175 [safe] Override sendmail's file 4176 safety checks. This will definitely 4177 compromise system security and should 4178 not be used unless absolutely 4179 necessary. 4180confREJECT_MSG - [550 Access denied] The message 4181 given if the access database contains 4182 REJECT in the value portion. 4183confRELAY_MSG - [550 Relaying denied] The message 4184 given if an unauthorized relaying 4185 attempt is rejected. 4186confDF_BUFFER_SIZE DataFileBufferSize 4187 [4096] The maximum size of a 4188 memory-buffered data (df) file 4189 before a disk-based file is used. 4190confXF_BUFFER_SIZE XScriptFileBufferSize 4191 [4096] The maximum size of a 4192 memory-buffered transcript (xf) 4193 file before a disk-based file is 4194 used. 4195confAUTH_MECHANISMS AuthMechanisms [GSSAPI KERBEROS_V4 DIGEST-MD5 4196 CRAM-MD5] List of authentication 4197 mechanisms for AUTH (separated by 4198 spaces). The advertised list of 4199 authentication mechanisms will be the 4200 intersection of this list and the list 4201 of available mechanisms as determined 4202 by the Cyrus SASL library. 4203confAUTH_REALM AuthRealm [undefined] The authentication realm 4204 that is passed to the Cyrus SASL 4205 library. If no realm is specified, 4206 $j is used. 4207confDEF_AUTH_INFO DefaultAuthInfo [undefined] Name of file that contains 4208 authentication information for 4209 outgoing connections. This file must 4210 contain the user id, the authorization 4211 id, the password (plain text), the 4212 realm to use, and the list of 4213 mechanisms to try, each on a separate 4214 line and must be readable by root (or 4215 the trusted user) only. If no realm 4216 is specified, $j is used. If no 4217 mechanisms are given in the file, 4218 AuthMechanisms is used. Notice: this 4219 option is deprecated and will be 4220 removed in future versions; it doesn't 4221 work for the MSP since it can't read 4222 the file. Use the authinfo ruleset 4223 instead. See also the section SMTP 4224 AUTHENTICATION. 4225confAUTH_OPTIONS AuthOptions [undefined] If this option is 'A' 4226 then the AUTH= parameter for the 4227 MAIL FROM command is only issued 4228 when authentication succeeded. 4229 See doc/op/op.me for more options 4230 and details. 4231confAUTH_MAX_BITS AuthMaxBits [INT_MAX] Limit the maximum encryption 4232 strength for the security layer in 4233 SMTP AUTH (SASL). Default is 4234 essentially unlimited. 4235confTLS_SRV_OPTIONS TLSSrvOptions If this option is 'V' no client 4236 verification is performed, i.e., 4237 the server doesn't ask for a 4238 certificate. 4239confLDAP_DEFAULT_SPEC LDAPDefaultSpec [undefined] Default map 4240 specification for LDAP maps. The 4241 value should only contain LDAP 4242 specific settings such as "-h host 4243 -p port -d bindDN", etc. The 4244 settings will be used for all LDAP 4245 maps unless they are specified in 4246 the individual map specification 4247 ('K' command). 4248confCACERT_PATH CACertPath [undefined] Path to directory 4249 with certs of CAs. 4250confCACERT CACertFile [undefined] File containing one CA 4251 cert. 4252confSERVER_CERT ServerCertFile [undefined] File containing the 4253 cert of the server, i.e., this cert 4254 is used when sendmail acts as 4255 server. 4256confSERVER_KEY ServerKeyFile [undefined] File containing the 4257 private key belonging to the server 4258 cert. 4259confCLIENT_CERT ClientCertFile [undefined] File containing the 4260 cert of the client, i.e., this cert 4261 is used when sendmail acts as 4262 client. 4263confCLIENT_KEY ClientKeyFile [undefined] File containing the 4264 private key belonging to the client 4265 cert. 4266confCRL CRLFile [undefined] File containing certificate 4267 revocation status, useful for X.509v3 4268 authentication. Note that CRL requires 4269 at least OpenSSL version 0.9.7. 4270confDH_PARAMETERS DHParameters [undefined] File containing the 4271 DH parameters. 4272confRAND_FILE RandFile [undefined] File containing random 4273 data (use prefix file:) or the 4274 name of the UNIX socket if EGD is 4275 used (use prefix egd:). STARTTLS 4276 requires this option if the compile 4277 flag HASURANDOM is not set (see 4278 sendmail/README). 4279confNICE_QUEUE_RUN NiceQueueRun [undefined] If set, the priority of 4280 queue runners is set the given value 4281 (nice(3)). 4282confDIRECT_SUBMISSION_MODIFIERS DirectSubmissionModifiers 4283 [undefined] Defines {daemon_flags} 4284 for direct submissions. 4285confUSE_MSP UseMSP [undefined] Use as mail submission 4286 program, see sendmail/SECURITY. 4287confDELIVER_BY_MIN DeliverByMin [0] Minimum time for Deliver By 4288 SMTP Service Extension (RFC 2852). 4289confREQUIRES_DIR_FSYNC RequiresDirfsync [true] RequiresDirfsync can 4290 be used to turn off the compile time 4291 flag REQUIRES_DIR_FSYNC at runtime. 4292 See sendmail/README for details. 4293confSHARED_MEMORY_KEY SharedMemoryKey [0] Key for shared memory. 4294confSHARED_MEMORY_KEY_FILE 4295 SharedMemoryKeyFile 4296 [undefined] File where the 4297 automatically selected key for 4298 shared memory is stored. 4299confFAST_SPLIT FastSplit [1] If set to a value greater than 4300 zero, the initial MX lookups on 4301 addresses is suppressed when they 4302 are sorted which may result in 4303 faster envelope splitting. If the 4304 mail is submitted directly from the 4305 command line, then the value also 4306 limits the number of processes to 4307 deliver the envelopes. 4308confMAILBOX_DATABASE MailboxDatabase [pw] Type of lookup to find 4309 information about local mailboxes. 4310confDEQUOTE_OPTS - [empty] Additional options for the 4311 dequote map. 4312confMAX_NOOP_COMMANDS MaxNOOPCommands [20] Maximum number of "useless" 4313 commands before the SMTP server 4314 will slow down responding. 4315confHELO_NAME HeloName If defined, use as name for EHLO/HELO 4316 command (instead of $j). 4317confINPUT_MAIL_FILTERS InputMailFilters 4318 A comma separated list of filters 4319 which determines which filters and 4320 the invocation sequence are 4321 contacted for incoming SMTP 4322 messages. If none are set, no 4323 filters will be contacted. 4324confMILTER_LOG_LEVEL Milter.LogLevel [9] Log level for input mail filter 4325 actions, defaults to LogLevel. 4326confMILTER_MACROS_CONNECT Milter.macros.connect 4327 [j, _, {daemon_name}, {if_name}, 4328 {if_addr}] Macros to transmit to 4329 milters when a session connection 4330 starts. 4331confMILTER_MACROS_HELO Milter.macros.helo 4332 [{tls_version}, {cipher}, 4333 {cipher_bits}, {cert_subject}, 4334 {cert_issuer}] Macros to transmit to 4335 milters after HELO/EHLO command. 4336confMILTER_MACROS_ENVFROM Milter.macros.envfrom 4337 [i, {auth_type}, {auth_authen}, 4338 {auth_ssf}, {auth_author}, 4339 {mail_mailer}, {mail_host}, 4340 {mail_addr}] Macros to transmit to 4341 milters after MAIL FROM command. 4342confMILTER_MACROS_ENVRCPT Milter.macros.envrcpt 4343 [{rcpt_mailer}, {rcpt_host}, 4344 {rcpt_addr}] Macros to transmit to 4345 milters after RCPT TO command. 4346confMILTER_MACROS_EOM Milter.macros.eom 4347 [{msg_id}] Macros to transmit to 4348 milters after the terminating 4349 DATA '.' is received. 4350confMILTER_MACROS_EOH Milter.macros.eoh 4351 Macros to transmit to milters 4352 after the end of headers. 4353confMILTER_MACROS_DATA Milter.macros.data 4354 Macros to transmit to milters 4355 after DATA command is received. 4356 4357 4358See also the description of OSTYPE for some parameters that can be 4359tweaked (generally pathnames to mailers). 4360 4361ClientPortOptions and DaemonPortOptions are special cases since multiple 4362clients/daemons can be defined. This can be done via 4363 4364 CLIENT_OPTIONS(`field1=value1,field2=value2,...') 4365 DAEMON_OPTIONS(`field1=value1,field2=value2,...') 4366 4367Note that multiple CLIENT_OPTIONS() commands (and therefore multiple 4368ClientPortOptions settings) are allowed in order to give settings for each 4369protocol family (e.g., one for Family=inet and one for Family=inet6). A 4370restriction placed on one family only affects outgoing connections on that 4371particular family. 4372 4373If DAEMON_OPTIONS is not used, then the default is 4374 4375 DAEMON_OPTIONS(`Port=smtp, Name=MTA') 4376 DAEMON_OPTIONS(`Port=587, Name=MSA, M=E') 4377 4378If you use one DAEMON_OPTIONS macro, it will alter the parameters 4379of the first of these. The second will still be defaulted; it 4380represents a "Message Submission Agent" (MSA) as defined by RFC 43812476 (see below). To turn off the default definition for the MSA, 4382use FEATURE(`no_default_msa') (see also FEATURES). If you use 4383additional DAEMON_OPTIONS macros, they will add additional daemons. 4384 4385Example 1: To change the port for the SMTP listener, while 4386still using the MSA default, use 4387 DAEMON_OPTIONS(`Port=925, Name=MTA') 4388 4389Example 2: To change the port for the MSA daemon, while still 4390using the default SMTP port, use 4391 FEATURE(`no_default_msa') 4392 DAEMON_OPTIONS(`Name=MTA') 4393 DAEMON_OPTIONS(`Port=987, Name=MSA, M=E') 4394 4395Note that if the first of those DAEMON_OPTIONS lines were omitted, then 4396there would be no listener on the standard SMTP port. 4397 4398Example 3: To listen on both IPv4 and IPv6 interfaces, use 4399 4400 DAEMON_OPTIONS(`Name=MTA-v4, Family=inet') 4401 DAEMON_OPTIONS(`Name=MTA-v6, Family=inet6') 4402 4403A "Message Submission Agent" still uses all of the same rulesets for 4404processing the message (and therefore still allows message rejection via 4405the check_* rulesets). In accordance with the RFC, the MSA will ensure 4406that all domains in envelope addresses are fully qualified if the message 4407is relayed to another MTA. It will also enforce the normal address syntax 4408rules and log error messages. Additionally, by using the M=a modifier you 4409can require authentication before messages are accepted by the MSA. 4410Notice: Do NOT use the 'a' modifier on a public accessible MTA! Finally, 4411the M=E modifier shown above disables ETRN as required by RFC 2476. 4412 4413Mail filters can be defined using the INPUT_MAIL_FILTER() and MAIL_FILTER() 4414commands: 4415 4416 INPUT_MAIL_FILTER(`sample', `S=local:/var/run/f1.sock') 4417 MAIL_FILTER(`myfilter', `S=inet:3333@localhost') 4418 4419The INPUT_MAIL_FILTER() command causes the filter(s) to be called in the 4420same order they were specified by also setting confINPUT_MAIL_FILTERS. A 4421filter can be defined without adding it to the input filter list by using 4422MAIL_FILTER() instead of INPUT_MAIL_FILTER() in your .mc file. 4423Alternatively, you can reset the list of filters and their order by setting 4424confINPUT_MAIL_FILTERS option after all INPUT_MAIL_FILTER() commands in 4425your .mc file. 4426 4427 4428+----------------------------+ 4429| MESSAGE SUBMISSION PROGRAM | 4430+----------------------------+ 4431 4432The purpose of the message submission program (MSP) is explained 4433in sendmail/SECURITY. This section contains a list of caveats and 4434a few hints how for those who want to tweak the default configuration 4435for it (which is installed as submit.cf). 4436 4437Notice: do not add options/features to submit.mc unless you are 4438absolutely sure you need them. Options you may want to change 4439include: 4440 4441- confTRUSTED_USERS, FEATURE(`use_ct_file'), and confCT_FILE for 4442 avoiding X-Authentication warnings. 4443- confTIME_ZONE to change it from the default `USE_TZ'. 4444- confDELIVERY_MODE is set to interactive in msp.m4 instead 4445 of the default background mode. 4446- FEATURE(stickyhost) and LOCAL_RELAY to send unqualified addresses 4447 to the LOCAL_RELAY instead of the default relay. 4448- confRAND_FILE if you use STARTTLS and sendmail is not compiled with 4449 the flag HASURANDOM. 4450 4451The MSP performs hostname canonicalization by default. As also 4452explained in sendmail/SECURITY, mail may end up for various DNS 4453related reasons in the MSP queue. This problem can be minimized by 4454using 4455 4456 FEATURE(`nocanonify', `canonify_hosts') 4457 define(`confDIRECT_SUBMISSION_MODIFIERS', `C') 4458 4459See the discussion about nocanonify for possible side effects. 4460 4461Some things are not intended to work with the MSP. These include 4462features that influence the delivery process (e.g., mailertable, 4463aliases), or those that are only important for a SMTP server (e.g., 4464virtusertable, DaemonPortOptions, multiple queues). Moreover, 4465relaxing certain restrictions (RestrictQueueRun, permissions on 4466queue directory) or adding features (e.g., enabling prog/file mailer) 4467can cause security problems. 4468 4469Other things don't work well with the MSP and require tweaking or 4470workarounds. For example, to allow for client authentication it 4471is not just sufficient to provide a client certificate and the 4472corresponding key, but it is also necessary to make the key group 4473(smmsp) readable and tell sendmail not to complain about that, i.e., 4474 4475 define(`confDONT_BLAME_SENDMAIL', `GroupReadableKeyFile') 4476 4477If the MSP should actually use AUTH then the necessary data 4478should be placed in a map as explained in SMTP AUTHENTICATION: 4479 4480FEATURE(`authinfo', `DATABASE_MAP_TYPE /etc/mail/msp-authinfo') 4481 4482/etc/mail/msp-authinfo should contain an entry like: 4483 4484 AuthInfo:127.0.0.1 "U:smmsp" "P:secret" "M:DIGEST-MD5" 4485 4486The file and the map created by makemap should be owned by smmsp, 4487its group should be smmsp, and it should have mode 640. The database 4488used by the MTA for AUTH must have a corresponding entry. 4489Additionally the MTA must trust this authentication data so the AUTH= 4490part will be relayed on to the next hop. This can be achieved by 4491adding the following to your sendmail.mc file: 4492 4493 LOCAL_RULESETS 4494 SLocal_trust_auth 4495 R$* $: $&{auth_authen} 4496 Rsmmsp $# OK 4497 4498Note: the authentication data can leak to local users who invoke 4499the MSP with debug options or even with -v. For that reason either 4500an authentication mechanism that does not show the password in the 4501AUTH dialogue (e.g., DIGEST-MD5) or a different authentication 4502method like STARTTLS should be used. 4503 4504feature/msp.m4 defines almost all settings for the MSP. Most of 4505those should not be changed at all. Some of the features and options 4506can be overridden if really necessary. It is a bit tricky to do 4507this, because it depends on the actual way the option is defined 4508in feature/msp.m4. If it is directly defined (i.e., define()) then 4509the modified value must be defined after 4510 4511 FEATURE(`msp') 4512 4513If it is conditionally defined (i.e., ifdef()) then the desired 4514value must be defined before the FEATURE line in the .mc file. 4515To see how the options are defined read feature/msp.m4. 4516 4517 4518+--------------------------+ 4519| FORMAT OF FILES AND MAPS | 4520+--------------------------+ 4521 4522Files that define classes, i.e., F{classname}, consist of lines 4523each of which contains a single element of the class. For example, 4524/etc/mail/local-host-names may have the following content: 4525 4526my.domain 4527another.domain 4528 4529Maps must be created using makemap(8) , e.g., 4530 4531 makemap hash MAP < MAP 4532 4533In general, a text file from which a map is created contains lines 4534of the form 4535 4536key value 4537 4538where 'key' and 'value' are also called LHS and RHS, respectively. 4539By default, the delimiter between LHS and RHS is a non-empty sequence 4540of white space characters. 4541 4542 4543+------------------+ 4544| DIRECTORY LAYOUT | 4545+------------------+ 4546 4547Within this directory are several subdirectories, to wit: 4548 4549m4 General support routines. These are typically 4550 very important and should not be changed without 4551 very careful consideration. 4552 4553cf The configuration files themselves. They have 4554 ".mc" suffixes, and must be run through m4 to 4555 become complete. The resulting output should 4556 have a ".cf" suffix. 4557 4558ostype Definitions describing a particular operating 4559 system type. These should always be referenced 4560 using the OSTYPE macro in the .mc file. Examples 4561 include "bsd4.3", "bsd4.4", "sunos3.5", and 4562 "sunos4.1". 4563 4564domain Definitions describing a particular domain, referenced 4565 using the DOMAIN macro in the .mc file. These are 4566 site dependent; for example, "CS.Berkeley.EDU.m4" 4567 describes hosts in the CS.Berkeley.EDU subdomain. 4568 4569mailer Descriptions of mailers. These are referenced using 4570 the MAILER macro in the .mc file. 4571 4572sh Shell files used when building the .cf file from the 4573 .mc file in the cf subdirectory. 4574 4575feature These hold special orthogonal features that you might 4576 want to include. They should be referenced using 4577 the FEATURE macro. 4578 4579hack Local hacks. These can be referenced using the HACK 4580 macro. They shouldn't be of more than voyeuristic 4581 interest outside the .Berkeley.EDU domain, but who knows? 4582 4583siteconfig Site configuration -- e.g., tables of locally connected 4584 UUCP sites. 4585 4586 4587+------------------------+ 4588| ADMINISTRATIVE DETAILS | 4589+------------------------+ 4590 4591The following sections detail usage of certain internal parts of the 4592sendmail.cf file. Read them carefully if you are trying to modify 4593the current model. If you find the above descriptions adequate, these 4594should be {boring, confusing, tedious, ridiculous} (pick one or more). 4595 4596RULESETS (* means built in to sendmail) 4597 4598 0 * Parsing 4599 1 * Sender rewriting 4600 2 * Recipient rewriting 4601 3 * Canonicalization 4602 4 * Post cleanup 4603 5 * Local address rewrite (after aliasing) 4604 1x mailer rules (sender qualification) 4605 2x mailer rules (recipient qualification) 4606 3x mailer rules (sender header qualification) 4607 4x mailer rules (recipient header qualification) 4608 5x mailer subroutines (general) 4609 6x mailer subroutines (general) 4610 7x mailer subroutines (general) 4611 8x reserved 4612 90 Mailertable host stripping 4613 96 Bottom half of Ruleset 3 (ruleset 6 in old sendmail) 4614 97 Hook for recursive ruleset 0 call (ruleset 7 in old sendmail) 4615 98 Local part of ruleset 0 (ruleset 8 in old sendmail) 4616 4617 4618MAILERS 4619 4620 0 local, prog local and program mailers 4621 1 [e]smtp, relay SMTP channel 4622 2 uucp-* UNIX-to-UNIX Copy Program 4623 3 netnews Network News delivery 4624 4 fax Sam Leffler's HylaFAX software 4625 5 mail11 DECnet mailer 4626 4627 4628MACROS 4629 4630 A 4631 B Bitnet Relay 4632 C DECnet Relay 4633 D The local domain -- usually not needed 4634 E reserved for X.400 Relay 4635 F FAX Relay 4636 G 4637 H mail Hub (for mail clusters) 4638 I 4639 J 4640 K 4641 L Luser Relay 4642 M Masquerade (who you claim to be) 4643 N 4644 O 4645 P 4646 Q 4647 R Relay (for unqualified names) 4648 S Smart Host 4649 T 4650 U my UUCP name (if you have a UUCP connection) 4651 V UUCP Relay (class {V} hosts) 4652 W UUCP Relay (class {W} hosts) 4653 X UUCP Relay (class {X} hosts) 4654 Y UUCP Relay (all other hosts) 4655 Z Version number 4656 4657 4658CLASSES 4659 4660 A 4661 B domains that are candidates for bestmx lookup 4662 C 4663 D 4664 E addresses that should not seem to come from $M 4665 F hosts this system forward for 4666 G domains that should be looked up in genericstable 4667 H 4668 I 4669 J 4670 K 4671 L addresses that should not be forwarded to $R 4672 M domains that should be mapped to $M 4673 N host/domains that should not be mapped to $M 4674 O operators that indicate network operations (cannot be in local names) 4675 P top level pseudo-domains: BITNET, DECNET, FAX, UUCP, etc. 4676 Q 4677 R domains this system is willing to relay (pass anti-spam filters) 4678 S 4679 T 4680 U locally connected UUCP hosts 4681 V UUCP hosts connected to relay $V 4682 W UUCP hosts connected to relay $W 4683 X UUCP hosts connected to relay $X 4684 Y locally connected smart UUCP hosts 4685 Z locally connected domain-ized UUCP hosts 4686 . the class containing only a dot 4687 [ the class containing only a left bracket 4688 4689 4690M4 DIVERSIONS 4691 4692 1 Local host detection and resolution 4693 2 Local Ruleset 3 additions 4694 3 Local Ruleset 0 additions 4695 4 UUCP Ruleset 0 additions 4696 5 locally interpreted names (overrides $R) 4697 6 local configuration (at top of file) 4698 7 mailer definitions 4699 8 DNS based blacklists 4700 9 special local rulesets (1 and 2) 4701 4702$Revision: 8.722 $, Last updated $Date: 2007/04/03 21:26:58 $ 4703