Databarracks - Databarracks provides secure disaster recovery, online backup and Infrastructure as a Service.
imapsync - Console-based utility for migrating IMAP mailboxes.
SysCloud - SysCloud offers backup solution helping businesses from data loss due to file corruption, accidental user error, and malicious acts.
MailStore - MailStore Home - A 100% free single-private-user desktop solution
Veeam - Veeam develops backup, disaster recovery and virtualization management software for VMware and Hyper-V virtual environments.
Fetchmail - The Fetchmail Project