AMSI Problem mit Exchnage 2016 CU 21

Hello,

I've also had this problem with Outlook client connectivity slowing down dramatically since installing Exchange 2016 CU21.  I disabled in web.config as you advised, but still had the problem.

I have cases open with Microsoft and Sophos; impossible for me to tell who's issue it is at this point.

I disabled AMSI on the agent with the "override" feature, as advised by Support.  Waited a while for the change to go through, but the Outlook connections remained slow.

Finally, today I decided to disable AMSI on my Exchange Server by policy from Sophos Central.  This time it worked!  Outlook connections are fast again.

Obviously this is a workaround.  I hope engineers at Sophos, Microsoft, or both can determine the root cause and fix it.  This is an important feature that I'd like to have enabled.

The processes in question would need to have restarted I suspect once the policy arrived such that the Sophos AMSI dll wasn't pulled into the process.

That's a good point, and I don't recall if we did that or not.  an IISRESET after disabling AMSI on the endpoint probably would have done it.

That's a good point, and I don't recall if we did that or not.  an IISRESET after disabling AMSI on the endpoint probably would have done it.