BlackMail is an Anti-Spam mailer proxy for use with popular MTA's like Sendmail, QMail, and SMail. It is highly configurable, very powerful, very fast, and runs on a large variety of platforms. It has undergone extensive testing, and this is the most stable release, now with Solaris support.
The BID software was designed to apply business rules to your email traffic. Business information can come from business applications, monitoring applications, or normal users requesting or providing data. The goal of the BID tool is to automate the dispatching of this information and to join a business-case with a responsible receiver. A receiver can be a human being or another BID server customized for a special business-case. The BID server was designed as a generic server using plugins to serve specific business-rules.
CG_spam_filter.pl provides a content filter program for the Stalker CommuniGate Pro mail server that seeks to limit the number of outgoing spam your local users can send and incoming spam your system can receive. In essence, it is a throttling script that starts rejecting mail once a certain threshold is reached, such as X messages or recipients per minute. It is difficult to catch spammers until after the fact (when they have already done lots of damage and spammed many users); this is simply an effort to stop them in their tracks in real-time so you can deal with them later.
COMDOM Antispam is a high-capacity platform designed for the requirements of ISPs and other large organizations that must fight spam. COMDOM is a powerful anti-spam system operating as a stand alone mail gateway with relay control, authentication, and load balancing support. The system consequently can be used together with mail servers or as a stand alone gateway for several mail servers. The robustness, flexibility, and the high data throughput capacity of COMDOM Antispam allow for the software to be deployed for a range of solutions.
CRM is a very powerful filtering and mutilation language based on regex operations. It is capable of classifying mail messages, syslogs, firewall logs, and other incoming streams of unbounded length. It has a very powerful sparse-spectral learning capability; given examples of multiple classes (say, business email, jokes, and spam), it can learn to discriminate the classes.
CRMME (prounounced "Cream-Me") processes mail from maildirs or mbox (UNIX-style mailboxes) into categories. It provides a simple procmail setup that lets the mail be sorted, and a cron job to learn new messages every night. It is provided as a wrapper around the CRM114 engine written in Python 2.2+ (2.1 with email module is acceptable and tested).