A.4 Mail Transport Agents

A.4 Mail Transport Agents

In this book, I describe how to use SpamAssassin in conjunction with several MTAs. The following sections point you to more information about each of those agents.

A.4.1 Sendmail

Sendmail has two primary web sites. The open source version maintained by the Sendmail consortium can be found at http://www.sendmail.org. Sendmail's commercial face is http://www.sendmail.com.

Sendmail's own antispam provisions are documented at http://www.sendmail.org/m4/anti_spam.html. If you're not a Sendmail guru, pick up Bryan Costales' book Sendmail (O'Reilly), the Sendmail bible. If you are a Sendmail guru, you probably already have a copy! Another good source is Frederick Avolio and Paul Vixie's Sendmail: Theory and Practice (Digital Press).

Sendmail's filtering architecture, milter, has led to the development of many filtering tools. The web site http://www.milter.org is the most comprehensive catalog of such filters.

A.4.2 Postfix

The home page for the Postfix MTA is http://www.postfix.org.

Two useful manuals for Postfix are Postfix: The Definitive Guide by Kyle Dent (O'Reilly) and The Book of Postfix by Ralf Hildebrandt and Patrick Koetter (No Starch Press).

A.4.3 qmail

The home page for the qmail MTA is http://www.qmail.org. The netqmail distribution of qmail includes the QMAILQUEUE patch, which is used by most SpamAssassin-integration solutions.

The online book Life with qmail (http://www.lifewithqmail.org) provides excellent documentation for qmail.

A.4.4 Exim

The home page for the Exim MTA is http://www.exim.org. The site includes a link to the Exim specification, which serves as the manual for the MTA. Those preferring a real book should purchase Philip Hazel's The Exim SMTP Mail Server: Official Guide for Release 4 (UIT Cambridge).