Chapter 15 Unified Threat Management for FortiOS 5.0 : Email filter : Email filter concepts : Email filter techniques : Detect phishing URLs in email
  
Detect phishing URLs in email
The FortiGate unit sends the URL links in email messages to FortiGuard to determine if the links are associated with a known phishing site. If such a link is detected, the link is removed from the message. The URL remains, but it is no longer a selectable hyperlink.