SpamAssassin has been ported for Windows by JAM Software. In combination with an MTA (e.g. Hamster or MS Exchange) it's a very powerful anti-spam solution.

Version: 3.4.1SpamAssassin is a mail filter which attempts to identify spam using a variety of mechanisms including text analysis, Bayesian filtering, DNS blocklists, and collaborative filtering databases.
License: Free
Operating System: Windows
Homepage: www.jam-software.com
Developed by:
SpamAssassin is a project of the Apache Software Foundation (ASF). SpamAssassin was adapted for Windows by JAM Software. In combination with a MTA (e.g.
Hamster or MS Exchange) it's a very powerful anti-spam solution.
The freeware contains, beside several modules, the following SpamAssassin components as executable files for Windows (.exe):
- spamassassin.exe (mail filter)
- spamd.exe (daemonized version of SpamAssassin)
- WinSpamC.exe (client for spamd)
- sa-update.exe (SpamAssassin rule updates)
- sa-learn.exe (trains bayes filter with spam / ham mail
What's New
Version 3.4.1: * Native 64 bit support has been integrated * SpamAssassin version 3.4.1 integrated * ActivePerl 5.8 replaced by Strawberry Perl 5.22 * Support for Windows XP and Server 2003 dropped * critical error in DNS-based spam tests removed * A few minor fixes have been incorporated.