This type of virus scanner operates in a manner like Praetor itself.  Conceptually it performs its scanning function as a SMTP mail relay, first receiving the message via SMTP and then analyzing the message and its attachments for any viral infection. If the message is found to be free of infection, it is transmitted to the receiving host.

In this environment, Praetor must be the very first SMTP mail host that receives the message from the Internet, before the virus scanner. There are two possible issues involving Praetor that CMS has seen to occur when trying to make Praetor coexist with a virus scanner on the same machine.

This will prevent a collision between the antivirus product and Praetor/IIS SMTP Server.

CMS has seen collisions on files in the Praetor OUT directory that are the temporary files created as messages are being received. This results in odd operational behavior with application event log entries indicating Praetor's inability to read and write to the message files.