acoc is a regular-expression based colour formatter for programs that display output on the command-line. It works as a wrapper around the target program, executing it and capturing the stdout stream. Optionally, stderr can be redirected to stdout, so that it, too, can be manipulated. acoc then applies matching rules to patterns in the output and applies colours to those matches.
Artica for Postfix is a secure Web interface for Postfix administration. It is designed to reduce the cost of creating and managing a full Linux mail server. It supports Postfix, Kaspersky Anti-spam, Kaspersky Anti-Virus, Bogofilter, Milter-greylist, SpamAssassin, Clam Antivirus, Amavis, OpenLDAP, SQLite library, Cyrus-imap, Procmail, Fetchmail, DnsMasq, Mailman, Sieve, Yorel script, QueueGraph, MailGraph, AWSTats, geoip, and more.
Attachment Ripper and Displacement System (aradis) is a filter that removes attachments from email. The removed attachment is sent to a specified resource for storage. The attachment is replaced with a notice of where the removed attachment may be found. The filter can also rename filenames for security. It uses GMime for MIME handling.
Autofiler is an automatic server-side mail filer application based on Bayesian text classification. In combination with an IMAP server, autofiler can file messages in folders automatically and with complete transparency. It uses (customized versions of) algorithms described in "A Statistical Approach to the Spam Problem".
B's Harmaa is Postfix policy server that implements greylisting and sender policy framework. What differentiates it from other similar programs is its unique autowhitelist feature. When a request for delivery of a message is received by Postfix via SMTP, the triplet CLIENT_IP / SENDER / RECIPIENT is built. If it is the first time that this triplet is seen or if the triplet was first seen less than one minute ago, then the message gets rejected with a temporary error. Spammers often will not try again later, even though it is required per RFC.