Today we are re-releasing the November 2024 SUs for Exchange Server. The original release of these SUs (released on 11/12/2024) introduced an issue with Exchange Server transport rules stopping after...
Updated Jan 28, 2025
Version 11.0
Blog Post
I can confirm issues with the transportservice, that exist in the V1 and V2.
In our case we got mail from internall app that includes .ical Files for calender entries. Those mails got all send to Poision Queue since V1 update. And sometime they cause a restart of Transport Service.
The transport process failed during message processing with the following call stack: Microsoft.Exchange.ExchangeSystem.InvalidTimeZoneException: Time zone id already exists
We suspended all queues removed the mails from that app and resumed the queues.
Today we had 4hours of downtime because of this. We therefore installed the V2 patch and hoped it would fix the issue but the issues stays the same. Even with the disabled P2From decetion via Settings override.
We now had to stopp the internal app to send mails at all. But from our understanding this could happen with any mail containing .ical attachment
can confirm that there is a problem with messages from google calendar getting into the poisoning queue - however, this happens both on servers with the November v1 fix and with the April one. I'm not sure if the problem is reproducible with v2.
Most of the messages have attachments .ics and are event cancellation messages.
Mix of exchange 2016 Cu23 and 2019 Cu14