MailStore - MailStore Home - A 100% free single-private-user desktop solution
Piler - Piler is an open source email archiving solution with all the necessary features for your enterprise
Gmvault - Backup the emails in your Gmail account.
KLS Mail Backup - KLS Mail Backup is an easy to use backup program that allows you to back up and restore your...
Mail Archiver X - Mail Archiver X protects one of your Mac-based small business' most important assets.
imapsync - Console-based utility for migrating IMAP mailboxes.