MailSecurity comes with four anti-virus engines namely Norman, BitDefender, Kaspersky, and McAfee. MailSecurity also has the built-in Trojan and Executable Scanner analyzer feature. It is the 6th step in the email sanitization process (refer to the MailFlow diagram). This feature is a must during the "blackout" period. Blackout is the period in which virus has arrived and yet no updates have been received from the vendor.

As you can see below, GFI MailSecurity was able to detect and quarantine messages containing the MyDoom virus as early as Jan 27, 2004 8:46am way before the Norman virus engine is updated with the MyDoom signature. The Norman virus signature update arrived on Jan 27, 2004 12:21pm (see the last line in the captured screenshot).