1d0cef73dSGregory Neil Shapiro<HTML> 2d0cef73dSGregory Neil Shapiro<HEAD> 3d0cef73dSGregory Neil Shapiro<TITLE>Filtering Mail with Sendmail</TITLE> 4d0cef73dSGregory Neil Shapiro</HEAD> 5d0cef73dSGregory Neil Shapiro<BODY> 640266059SGregory Neil Shapiro<!-- 7*4313cc83SGregory Neil Shapiro$Id: index.html,v 1.14 2013-11-22 20:51:39 ca Exp $ 840266059SGregory Neil Shapiro--> 940266059SGregory Neil Shapiro 10d0cef73dSGregory Neil Shapiro<H1>Filtering Mail with Sendmail</H1> 1140266059SGregory Neil Shapiro 1240266059SGregory Neil Shapiro<!-- 13d0cef73dSGregory Neil Shapiro<P><B>Disclaimer</B>: 1440266059SGregory Neil ShapiroThis preliminary API description is provided for review only. This 1540266059SGregory Neil Shapirospecification may change based on feedback from reviewers, and does 1640266059SGregory Neil Shapironot bind Sendmail to offer this functionality in any release. 1740266059SGregory Neil Shapiro--> 1840266059SGregory Neil Shapiro 19d0cef73dSGregory Neil Shapiro<H2>Introduction</H2> 2040266059SGregory Neil Shapiro 2140266059SGregory Neil Shapiro<P> 2240266059SGregory Neil ShapiroSendmail's Content Management API (milter) provides third-party 2340266059SGregory Neil Shapiroprograms to access mail messages as they are being processed by the 2440266059SGregory Neil ShapiroMail Transfer Agent (MTA), allowing them to examine and modify message 2540266059SGregory Neil Shapirocontent and meta-information. Filtering policies implemented by 2640266059SGregory Neil ShapiroMilter-conformant filters may then be centrally configured and 2740266059SGregory Neil Shapirocomposed in an end-user's MTA configuration file. 2840266059SGregory Neil Shapiro 29d0cef73dSGregory Neil Shapiro<P> 3040266059SGregory Neil ShapiroPossible uses for filters include spam rejection, virus 3140266059SGregory Neil Shapirofiltering, and content control. In general, Milter seeks to address 3240266059SGregory Neil Shapirosite-wide filtering concerns in a scalable way. Individual users' mail 3340266059SGregory Neil Shapirofiltering needs (e.g. sorting messages by subject) are left to 34d0cef73dSGregory Neil Shapiroclient-level programs such as <A href="http://www.procmail.org">Procmail</A>. 3540266059SGregory Neil Shapiro 3640266059SGregory Neil Shapiro<P> 3740266059SGregory Neil ShapiroThis document is a technical introduction intended for those 3840266059SGregory Neil Shapirointerested in developing Milter filters. It includes: 39d0cef73dSGregory Neil Shapiro<UL> 40d0cef73dSGregory Neil Shapiro<LI>A description of Milter's design goals. 4140266059SGregory Neil Shapiro 42d0cef73dSGregory Neil Shapiro<LI>An explanation of Milter application architecture, including 4340266059SGregory Neil Shapirointeractions between the support library and user code, and between 4440266059SGregory Neil Shapirofilters and the MTA. 4540266059SGregory Neil Shapiro 46d0cef73dSGregory Neil Shapiro<LI>A specification of the C application programming interface. 47d0cef73dSGregory Neil Shapiro<LI>An example of a simple Milter filter. 48d0cef73dSGregory Neil Shapiro</UL> 4940266059SGregory Neil Shapiro 50d0cef73dSGregory Neil Shapiro<H2>Contents</H2> 5140266059SGregory Neil Shapiro 52d0cef73dSGregory Neil Shapiro<UL> 53d0cef73dSGregory Neil Shapiro<LI><A href="design.html">Architecture</A> 54d0cef73dSGregory Neil Shapiro<UL> 55d0cef73dSGregory Neil Shapiro <LI>Design Goals 56d0cef73dSGregory Neil Shapiro <LI>Implementing Filtering Policies 57d0cef73dSGregory Neil Shapiro <LI>MTA - Filter communication 58d0cef73dSGregory Neil Shapiro</UL> 59d0cef73dSGregory Neil Shapiro<LI><A href="overview.html">Technical Overview</A> 60d0cef73dSGregory Neil Shapiro<UL> 61d0cef73dSGregory Neil Shapiro <LI>Initialization 62d0cef73dSGregory Neil Shapiro <LI>Control flow 63d0cef73dSGregory Neil Shapiro <LI>Multithreading 64d0cef73dSGregory Neil Shapiro <LI>Resource Management 65d0cef73dSGregory Neil Shapiro <LI>Signal Handling 66d0cef73dSGregory Neil Shapiro</UL> 67d0cef73dSGregory Neil Shapiro<LI><A href="api.html">API Documentation</A> 68d0cef73dSGregory Neil Shapiro<UL> 69d0cef73dSGregory Neil Shapiro <LI>Library Control Functions 70d0cef73dSGregory Neil Shapiro <LI>Data Access Functions 71d0cef73dSGregory Neil Shapiro <LI>Message Modification Functions 72d0cef73dSGregory Neil Shapiro <LI>Callbacks 73d0cef73dSGregory Neil Shapiro</UL> 74d0cef73dSGregory Neil Shapiro<LI><A href="installation.html">Installation and Configuration</A> 75d0cef73dSGregory Neil Shapiro<UL> 76d0cef73dSGregory Neil Shapiro <LI>Compiling and Installing Your Filter 77d0cef73dSGregory Neil Shapiro <LI>Configuring Sendmail 78d0cef73dSGregory Neil Shapiro</UL> 79d0cef73dSGregory Neil Shapiro<LI><A href="sample.html">A Sample Filter</A> 80d0cef73dSGregory Neil Shapiro<!-- <LI><A href="other.html">Other Sources of Information</A> --> 81d0cef73dSGregory Neil Shapiro</UL> 8240266059SGregory Neil Shapiro 83d0cef73dSGregory Neil Shapiro<HR size="1"> 84d0cef73dSGregory Neil Shapiro<FONT size="-1"> 855dd76dd0SGregory Neil ShapiroCopyright (c) 2000, 2001, 2003 Proofpoint, Inc. and its suppliers. 8640266059SGregory Neil ShapiroAll rights reserved. 87d0cef73dSGregory Neil Shapiro<BR> 8840266059SGregory Neil ShapiroBy using this file, you agree to the terms and conditions set 895ef517c0SGregory Neil Shapiroforth in the LICENSE. 90d0cef73dSGregory Neil Shapiro</FONT> 91d0cef73dSGregory Neil Shapiro</BODY> 92d0cef73dSGregory Neil Shapiro</HTML> 93