Appendix A. Resources

This appendix lists useful online resources for further information about spam, spam-filtering, SpamAssassin, each of the mail transport agents discussed in this book, and several other SpamAssassin-related software packages.

General Spam Resources

“Help! I’ve been spammed! What do I do?”—originally written by Chris Lewis and maintained by Greg Byshenk—is an helpful (if dated) guide to spam and spam-prevention for the beginner. Find it at

Internet Request For Comments (RFC) documents describe proposed standards for the Internet. You can get RFCs from Some notable RFCs related to spam and spam filtering include

RFC 2822: Internet Message Format

The basic document that describes the formatting of email messages.

RFC 2821: Simple Mail Transfer Protocol

Explains SMTP, the protocol used to transfer email from system to system.

RFC 2505: Anti-spam Recommendations for Internet MTAs

Describes a set of best practices for mail servers.

The SPAM-L FAQ, maintained by Doug Muth at, provides information about the SPAM-L mailing list, one of the oldest discussion forums for spam fighters. is a long-standing site with information for antispam advocates and system adminstrators.

The Coalition Against Unsolicited Commercial Email (CAUCE) has a web site at CAUCE focuses primarily on advocacy and legislation.

The groups in ...

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