Fast Greylist daemon as a Postfix Access Policy Delegation Service with a variable extendable rule set. The rules are used for whitelisting, blacklisting and greylisting based on information from the SMTP dialog on a "per delivery attempt" basis.
PerlPop3 is a pop3 server written entirely in Perl. It is not memory hog as other pop3 servers, and pretty fast processing thousands of mails. Can be extended to use a database (and use APOP authentication). As a script can be modified as per your ne
An easy to use, scalable, extendible mailing list manager created in PHP. Has user management, job queuing and staggering. Uses ADODb Lite access layer for fast effecient access to your database, (currently only MySQL support included).