Now that the September 2021 Cumulative Updates (CUs) for Exchange Server 2019 and Exchange Server 2016 have been released, customers around the world now have access to a new security feature in Exch...
Updated Oct 01, 2021
Version 1.0
Blog Post
Nino_Bilic we are having the same issue as HFlet500 and gghiq1040. This started 2022-06-09T19:15:08.905Z for us. The only difference is I can't seem to find that signing certificate anywhere. There isn't really anything useful in the logs. It was working at 6:15 PM when it checked in then an hour later when it checked in again it stopped and hasn't been working since. I have restarted the service. Any ideas on how to fix this? Thank you.
:LogLevel=Error;'S:Message=Exception encountered while fetching mitigations : This XML is not deemed safe to consume since Response xml''s signing cert is invalid or not from microsoft';S:Source=Microsoft.Exchange.Mitigation.Service.Mitigations.MitigationEngine