Praetor can run with all virus scanning software that performs that function as a relay.
Even more important, everything can run on the same machine, just as long as the AV software can be configured to receive and send on different ports. Simply let Praetor receive from the Internet on the normal port 25, and deliver it to the AV software on port 28. In turn, the AV will deliver to IMS on a different port. We have many customers with this configuration. Since Praetor adds the ability to reject messages at the transport level while the message is being transmitted and even before it has been received, it does more than the AV product.