Chapter 15 Unified Threat Management for FortiOS 5.0 : Email filter : Email filter concepts : Email filter techniques : Email address black/white list check
  
Email address black/white list check
The FortiGate unit compares the sender email address, as shown in the message envelope MAIL FROM, to the addresses in the email address black/white list specified in the email filter profile. If a match is found, the FortiGate unit will take the action configured for the matching black/white list entry.