Bayesian Mail Filter
bmf is a self contained and extremely efficient Bayesian mail filter. See Paul Graham`s article "A Plan for Spam" for background

Communications::Email::Filters

PASP - Python Anti-Spam Proxy
You can filter your email using a bayesian like statistical method. Written in 100% Python, easily extensible, and is used

Communications::Email::Filters

Spamicide Sendmail filter
uses probability calculations to arrive at the statistically correct answer for whether a certain text is "spam" text or

Communications::Email::Filters

POPFile - Automatic Email Classification
POPFile is an email classification tool with a Naive Bayes classifier, POP3, SMTP, NNTP proxies and IMAP filter and a web

Communications::Email::Filters

mboxsplit -- the FAST mailbox splitter
mailbox splitter designed to assist your anti-virus software and replace for free some >=$3000 mail server software components

Communications::Email::Email Clients (MUA)
Communications::Email::Filters
Internet
Security

The Spam Secretary
The Spam Secretary is an anti-spam email filter based on the article at http://www.paulgraham.com/spam.html. It is written

Communications::Email::Filters

SmartSieve
SmartSieve is a web based graphical user interface for creating and managing sieve scripts for mail filtering and vacation

Communications::Email::Filters
System::Systems Administration

bogofilter -- Fast Bayesian Spam Filter
The bogofilter package implements a fast Bayesian spam filter as suggested by Paul Graham in "A Plan For Spam" . It is written

Communications::Email::Filters

JoeEmail
How Joe deals with Spam. JoeEMail is a lightly featured email client for windows that uses a Bayesian probability filter

Communications::Email::Email Clients (MUA)
Communications::Email::Filters

Bayespam
Bayespam is a spam filter for Qmail implemented in Perl. Based on Paul Graham`s "A Plan for Spam" paper, Bayespam uses Bayesian

Communications::Email::Filters