Hi, I have implemented the SMTP filter on my ISA server, I am receiving Event ID 1722: An unknown SMTP command occurred. MS have posted a Q article Q 312 357 CAUSE If the SMTP content application filter is installed, you must explicitly state which SMTP commands are permitted. Event 1722 occurs if you do not explicitly state the SMTP commands that are in use. RESOLUTION To resolve this issue, add the appropriate SMTP command in the application filter. Or, you can disable SMTP content filtering if it is not necessary. Basically my problem is that the SMTP command that was issued does not seem to be logged anywhere so I am unable to see which command caused the email to be disallowed. I need a listing of the correct SMTP commands (or pointed to the log that holds the suspect SMTP command) needed to allow email from most SMTP servers. Any help would be greatly appreciated. Nathaniel Horth