MailStore - MailStore Home - A 100% free single-private-user desktop solution
SpamAssassin - Use this program to "Unspam" your mailbox(es).
Gmvault - Backup the emails in your Gmail account.
MailScanner - MailScanner is a open source email security system design for Linux-based email gateways.
Mail Backup X - Your one stop mail backup and archiving tool for Mac.
Rspamd - Rspamd is an advanced spam filtering system that allows evaluation of messages by a number of rules...