MailStore - MailStore Home - A 100% free single-private-user desktop solution
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?
Gmvault - Backup the emails in your Gmail account.
Paubox - Paubox provides HIPAA compliant email encryption without the hassle of extra steps.
Got Your Back - Got Your Back (GYB) is a command line tool that backs up and restores your Gmail account.
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.