Openly developed software to block, filter, and revent SPAM (UCE/UBE) via mailing lists, individuals, or newsgroups.
Regular Websites
Features details about the Anti-Spam SMTP Proxy (ASSP) Server project; includes FAQ for whitelists, Bayesian filtering, and more. - ASSP
http://assp.sourceforge.net/
An openly developed, scalable, and content-based spam filter designed for multi-user enterprise systems. - DSPAM Project
http://www.nuclearelephant.com/
An Open Source server-side spam filter providing exceptional and effective email filtering for unsolicited emails; complete with FAQ and other information. - Greylite
http://www.greylite.net/
An openly developed email plugin which helps to filter spam; fully trainable and extendable. Contains installation details, and more. - Kopete Anti-Spam Plugin
http://kopeteantispam.sourceforge.net/
Developed and distributed by Symantec Corporation, Norton is a computer program designed to provide malware prevention and removal during a subscription period, as well as e-mail spam filtering and phishing protection. Its products are described, and customers may subscribe from the site. A webmaster affiliate program is also outlined. - Norton from Symantec
http://www.symantecstore.com/
An automatic email classification application which sorts your email messages and fights spam; complete with download and installation details. - POPFile
http://getpopfile.org/
An openly developed, GNU GPL-licensed application created to detect and block spam using identifying digests of message. - Pyzor
http://pyzor.sourceforge.net/
An openly developed anti-spam application, licensed under GNU General Public License (GPL); complete with download and installation information, as well as FAQ. - Spam Blocker
http://www.untangle.com/Spam-Blocker
A Bayesian spam filter which filters emails received by using artificial intelligence and server blacklists. - Spam Bully
http://www.spambully.com/
An openly developed spam filter; contains download and documentation information, as well as FAQ, bug fixes, and recent enhancement details. - SpamAssassin
http://spamassassin.apache.org/
An openly developed and fully extendable spam filter system; licensed under GPL. Features download and documentation information, and more. - Spamato
http://www.spamato.net/
A Bayesian Anti-Spam classifier; written in Python with a probability-based mail filter that includes a Microsoft Outlook plug-in. Available for Linux, Mac OSX, Unix, and Windows. - SpamBayes
http://spambayes.sourceforge.net/
A Bayesian spam filter which makes inboxes readable again through bayesian filtering. Contains download and installation information and documentation. - SpamProbe
http://spamprobe.sourceforge.net/