SpamHero - SpamHero is a professional spam filtering accuracy while lowering the cost to domain and business owners.
SpamExperts - SpamExperts applies its proprietary smart technologies to eliminate spam, virus and malware mail before it reaches your network.
SpamExperts Outgoing Filter - The outbound email filtering prevents spam from being unknowingly sent out of your network through a compromised account or script.
Mimecast - Utilities, Application Utilities, and Security
SPAMfighter - SPAMfighter and Microsoft have built the strongest and most effective anti spam filter for Outlook, Windows Live Mail, Outlook Express & Thunderbird
SpamTitan - Comprehensive Email Protection. 99.99% Spam Detection. Blocks phishing, viruses, malware and other email threats.