Spamihilator - The free Anti-Spam-Filter Spamihilator removes more than 98% of spam mails before they even get into your inbox.
Barracuda Email Security Gateway - Barracuda's Email Security Gateway is a powerful antivirus filter specifically designed to identify and eliminate email-borne threats, stopping hazards before they reach the network.
Mailwasher - Over 8 million people use MailWasher as their spam filter
Symantec Email Security.cloud - Symantec Email Security.cloud provides always-on, inbound and outbound email security against malware, targeted attacks, and advanced threats
SPAMfighter - SPAMfighter and Microsoft have built the strongest and most effective anti spam filter for Outlook, Windows Live Mail, Outlook Express & Thunderbird
Cisco Email Security - Cisco Email Security protects against ransomware, business email compromise, spoofing, and phishing.