SAwin32 — SpamAssassin for Win32

SpamAssassin is one of the best spam filters and it is also free. However, it usually runs on corporate UNIX servers. The goal of this open source project is to release special builds of SpamAssassin that run on Windows platform.

Download SAwin32 — SpamAssassin POP3 Proxy for Win32, a free personal anti-spam filter based on SpamAssassin™, SAproxy™, DCC and Razor.

Also, you can download SpamAssassin for Win32 command-line tools, a native Windows build of spamassassin and spamd/spamc. (Especially useful on mail servers!)

Version has been released!

Free downloads:

Support SAwin32 project


SAwin32 is a POP3 proxy that includes SAproxy graphical user interface and SpamAssassin engine. This spam filter stands between your email reader and the POP3 (incoming) mail server. It can

  1. study the message and check whether it matches patterns common for spam;
  2. contact online "blacklists" (DNSBL) to verify whether the message has arrived from a known spam source;
  3. contact online databases DCC and Razor (Cloudmark) which collect the "fingerprints" of millions of known spam messages;
  4. automatically learn how to tell spam from non-spam (statistical analysis);
  5. automatically whitelist frequent senders;
  6. easily configure basic settings with the help of a user-friendly interface;
  7. support custom rules (although that requires reading SpamAssassin documentation).

The result is very high precision of email classification: the filter properly identifies and marks nearly all spam messages, while the false positive rate, that is, the amount of incorrectly classified legitimate mail, is virtually zero.

SAwin32 supports SSL and works with any email client (Outlook, Eudora, etc.), but only with POP3 mail accounts. Thus, it will not work with web-based email (such as Hotmail), IMAP, Microsoft Exchange, Lotus Notes, etc. In order to use this filter, you need to know the name of your POP3 (incoming) mail server. It typically looks like pop.isp.tld. You can find it in the configuration of your email client or by asking your Internet Service Provider.

The history of the filter started in 2002, when Dan McDonald successfully ported SpamAssassin to Microsoft Windows by writing pop3proxy Perl script that was acting as a proxy between the mail client and the POP3 server. Further work on this script lead to the release of the free spam filter SAproxy and then commercial SAproxy Pro. Soon after the release in 2003, Consumer Reports declared SAproxy the best personal anti-spam solution for Windows. However, after Yahoo! acquired Stata Labs at the end of 2004, they announced that SAproxy was discontinued. In 2005 Eugene Pivovarov adapted free SAproxy v1.2 so that it started to work with the latest versions of SpamAssassin, DCC and Vipul's Razor. After the project moved to SourceForge, it got the name SAwin32.

Download SAwin32 v3.2.3.3, which contains SpamAssassin v3.2.3.

SpamAssassin for Win32 command-line tools

As it has already been mentioned, the primary goal of this project is to release special builds of SpamAssassin that run on Windows platform. The original SpamAssassin is a filter that takes the message from standard input and returns the processed message to standard output. The set of SpamAssassin for Win32 command-line tools includes two utilites that work like that: spamassassin.exe and spamc.exe. The difference between them is that the latter requires the resident daemon spamd.exe and achieves much better performance, which is particularly important for mail servers.

Download SpamAssassin for Win32 command-line tools based on SpamAssassin v3.2.3.


What if the filter has missed a spam message? You can help the filter by training it! Just download sa-learn add-on and read enclosed instructions.


Just like antivirus scanners, spam filters apply certain rules to the messages that they process. Thus, it makes sense to update them from time to time. Since the spammers are not awfully creative, their techniques evolve very slowly, therefore, the updates certainly do not need to be perfomed on the daily basis. Note that as long as this project is alive, new file releases should be posted once every few months as well.

To update SpamAssassin filter rules, download sa-update add-on and read enclosed instructions.


Questions? Comments? Your feedback is welcome!