SpamTitan - Comprehensive Email Protection. 99.99% Spam Detection. Blocks phishing, viruses, malware and other email threats.
imapsync - Console-based utility for migrating IMAP mailboxes.
MailCleaner - Cloud & on-premise anti spam software for businesses
MailStore - MailStore Home - A 100% free single-private-user desktop solution
Vade Secure - Email security to protect against email-borne phishing, spear phishing, malware, and ransomware. Email security and management based on artificial intelligence.
Fetchmail - The Fetchmail Project