Jay's right, here is the line from Cisco
Q. Is there a way to filter email packets on the Cisco Secure PIX Firewall? For instance, can I have the Cisco Secure PIX Firewall filter the "I luv you" virus?
A. The Cisco Secure PIX Firewall does not perform content filtering at the Application layer. In other words, it does not inspect the data portion of the TCP packet. Therefore, it cannot filter email content. Most modern-day mail servers can filter at the application layer.
