imapsync - Console-based utility for migrating IMAP mailboxes.

NeoCertified Secure Email - NeoCertified is a solution that provides secure email encryption for businesses and organizations across all industries, including healthcare, finance, legal, non-profit and education.

Gmvault - Backup the emails in your Gmail account.

Virtru - Virtru is your data privacy force field, wrapping and protecting emails and files wherever they're shared. Easy-to-use data security software for business. People also askIs Virtru Hipaa compliant?

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.

Proofpoint Email Encryption - As email is the preferred medium for business communications, preventing confidential information from being leaked in outbound email messages must be a top priority in order to lower the risk of a data breach.