Anti-Spam SMTP Proxy Server implements multiple spam filters
SMTP email proxy and relay server
Powerful Open Source Email Marketing app with analytics & segmentation
Client daemon to move mail from POP and IMAP to your local computer
mailbox synchronizer
Fast Bayesian spam filter along lines suggested by Paul Graham
IGSuite is a web-ajax-based Integrated Groupware Suite
Strong Email & Apache Log Analysis with Active Security Features
Remote anti spam utility
Unified Communications Server