SpamAssassin - Use this program to "Unspam" your mailbox(es).
SpamTitan - Comprehensive Email Protection. 99.99% Spam Detection. Blocks phishing, viruses, malware and other email threats.
Rspamd - Rspamd is an advanced spam filtering system that allows evaluation of messages by a number of rules...
Sanebox - SaneBox is a cloud-based service that allows users to filter and manage their emails.
Oikik Antispam - Oikik is a cloud-based email filtering service that works with your existing email service.
ZeroSpam - Cloud email security & anti-spam solution