Extensible Messaging Platform Anti-Spam Filter 5.5
Server based Anti-Spam Filter protects organizational mail servers (Exchange Server, Novell GroupWise, Lotus Domino, Sendmail, etc) from spam, email-borne viruses (including dangerous auto-launch viruses) and objectionable content using contextual pattern signatures (not simple keywords). The use of contextual signatures results in high success and extremely low false-positive rates.

No Spam Today! for Servers 3.1.5.1
NoSpamToday is an e-mail spam filter (SMTP/POP3) compatible to every known mail server software. NoSpamToday includes the award-winning SpamAssassin filter, an attachment blocker, and an RBL filter. 3rd-party virus scanners can be easily integrated into the filtering pipeline. Traffic limiting protects your mail service from flooding or directory harvest attacks. Statistics and reports are available in real-time.

No Spam Today! for Servers Freeware 3.1.5.1
NoSpamToday is a e-mail spam filter (SMTP/POP3) compatible to every known mail server software. NoSpamToday includes the award-winning SpamAssassin filter, an attachment blocker, and an RBL filter. 3rd-party virus scanners can be easily integrated into the filtering pipeline. Traffic limiting protects your mail service from flooding or directory harvest attacks. Statistics and reports are available in real-time.

GFI MailDefense Suite 1
Anti-virus, anti-spam & anti-phishing suite for Exchange server. It uses multiple technologies, such as Bayesian filtering to remove spam and up to five anti-virus engines to clean inbound email from viruses and malware. GFI MailDefense Suite offers the highest spam detection rate and a low rate of false positives. It is easy to deploy and ships at an unbeatable price.