Mail Archiva - Email Archiving

MailArchiva is a powerful, full featured email archiving (email archiver) and compliance solution for mail systems. It stores all incoming, outgoing and internal emails for long term storage. It complies with email archiving regulations. Search support is provided to retrieve mails faster. Duplicate messages are identified and only one copy of the mail is stored. MailArchiva is capable of archiving emails to a wide range of network storage devices and storage arrays.

Sourceforge: http://sourceforge.net/projects/openmailarchiva/