Hexamail Guard

Hexamail Guard is a server based software antispam filter for the Windows and Linux platforms.
Acting as a gateway at the SMTP level or as a plugin for Microsoft Exchange Server, it supports most common anti spam filtering techniques including:
*Bayesian pattern matching
*Keyword/String/Expression
*Header checks
*DNS based blocklists
*URL blocklists
*Image analysis
*Hosted image blocking
*Sender analysis using neural network
*Cloaking/Phishing detection
*Challenge-Response
*Blacklisting
*User-configurable whitelists
*Automatic Internet updates to blocking features
*Honeypot Matching
*Grey Listing
*Detection of Spam NDRs
*Domain Keys
*Sender Policy Framework
*Optional antivirus scanning

In addition it supports external POP3 account downloading and filtering, a spam quarantine with multiple options for processing including: listing, forwarding, blocking, marking/tagging and deletion. Users can review their own spam through a web-based quarantine view.

External links

* [http://www.hexamail.com/hexamailguard/ Hexamail Guard web site]