SpamFiltering

This is a collection of tips and tricks to get rid of spam. Please describe your trick as fully as possible. If you have any information about false positive risk please make that clear as well.

ACL Related Tricks

• ACL HELO Tricks
• Sender/Recipient Verification
• Blocking with Blacklists
• Delay SMTP transactions
• Rcpt ACL
• Data ACL
• Block outgoing spam
• A package of checks
• Map IP addresses to country codes

Spam Assassin

• Maildir Spam Delivery

Greylisting

• Simple Greylisting with Exim
• Grey Listing Mini Tutorial
• E-Z Grey Listing Without A Database (using Perl)
• Greylisting without a database and without Perl: using ${dlfunc and using ${run
• Heiko Schlitterman's implementation
• Jakob Hirsch's Simple Greylisting with SQLite
• greylisting daemon using SQLite
• Greylisting using MySQL and stored procedures
• ddgrey - dynamic and optionally distributed greylisting for exim4 (beta)
• Greylisting using only Exim’s builtin 'seen' functionality
• More implementations at Spam Links, see archived version

(Remember when searching for further implementations that some use "grey" and others "gray" in their descrciptions).

Other Tricks

• Ideas for how to use Exim filters on delivery
• Use addresses with limited validity

External Sites with Good Spam Filtering Info

• Tor Slettnes Exim Spam Filtering Site, see archived version
• Marc Perkel's Spam Filtering Tricks
• Exim configuration at the University of Cambridge
• Spam Assassin
• Spam Probe
• Dynamic IP address filtering, see archived version
• Spam Assassin Basics for CPanel users, see archived version
• ACL snippets, see archived version
• dlfunc functions for Exim, see archived version
• More ACL snippets, see archived version

External Sites with ${dlfunc{file}{function}{<arg>}{<arg>}...}

• ${dlfunc dspam
• ${dlfunc milter
• ${dlfunc spamd
• ${dlfunc spamoborona2