imapsync - Console-based utility for migrating IMAP mailboxes.

VSquare - Vsquare is a Vmware and Hyper-V-based data protection, disaster recovery, and business continuity solution that provides businesses with a complete, affordable solution for protecting their data and ensuring continuity in the event of a disaster.

Gmvault - Backup the emails in your Gmail account.

Bacula Enterprise - A physical, virtual and cloud data center backup software for data centers. Bacula Enterprise Edition is the best open source backup software.

Cryoserver - Cryoserver is an all-in-one email archiving solution that empowers you to preserve your email in a tamper-evident archive, making you transform your data into a useful archive for everyday use.

CloudEndure - CloudEndure provides cloud migration and cloud disaster recovery for any application.