WFBS provides two ways to combat spam—Email Reputation and Content Scanning.

The Messaging Security Agent uses the following components to filter email messages for spam and phishing incidents:

  • Trend Micro Anti-Spam Engine

  • Trend Micro spam pattern files

Trend Micro updates both the engine and pattern file frequently and makes them available for download. The Security Server can download these components through a manual or scheduled update.

The anti-spam engine uses spam signatures and heuristic rules to filter email messages. It scans email messages and assigns a spam score to each one based on how closely it matches the rules and patterns from the pattern file. The Messaging Security Agent compares the spam score to the user-defined spam detection level. When the spam score exceeds the detection level, the agent takes action against the spam.

For example: Spammers often use many exclamation marks or more than one consecutive exclamation mark(!!!!) in their email messages. When the Messaging Security Agent detects a message that uses exclamation marks this way, it increases the spam score for that email message.


In addition to using Anti-Spam to screen out spam, you can configure Content Filtering to filter message header, subject, body, and attachment information to filter out spam and other undesirable content.

Users cannot modify the method that the anti-spam engine uses to assign spam scores, but they can adjust the detection levels used by the Messaging Security Agent to decide what is spam and what is not spam.


Microsoft Outlook may automatically filter and send messages that the Messaging Security Agent detected as spam to the Junk Mail folder.