My "trick" for IMAP scanning, Jay, is to ask the hosting service to disable anti-spam for your domain and, if possible, limit accepted traffic to the IP of your UTM. Change your MX record to point at your UTM. Now the traffic is scanned before it reaches your mail service. Can that work for you?
Cheers - Bob
Sophos UTM Community Moderator Sophos Certified Architect - UTM Sophos Certified Engineer - XG Gold Solution Partner since 2005
Bob, this might be possible with a domain I have control over, but no domains like gmail, yahoo, etc. All of which are accessed by clients on the local network.
I don't think that running Gmail or Yahoo Mail through UTM scans would be worth the effort, Jay. My university recently switched the alumni email domain over to Gmail. Before, I got dozens of spams every month sent to BAlfson@alumni.university.edu, but now I never get any.
Cheers - Bob
Sophos UTM Community Moderator Sophos Certified Architect - UTM Sophos Certified Engineer - XG Gold Solution Partner since 2005
