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.

Thunderbird - Thunderbird is a free email application that's easy to set up and customize - and it's loaded with great features!

Gmvault - Backup the emails in your Gmail account.

Microsoft Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.

imapsync - Console-based utility for migrating IMAP mailboxes.

Mailspring - Mailspring is a mail client for Mac, Windows and Linux.