Exchange 2010: Mapi session exceeded the maximum of 250 objects of type "objtMessage"
In Exchange 2010, we might come across the following error message logged consistently in the event log for a mailbox:
- Mapi session exceeded the maximum of 250 objects of type "objtMessage"
https://collaborationpro.com/wp-content/uploads/2018/05/eventid9646.png
The best option will be to investigate outlook add-ins or AV or something scanning the mailbox on the machine.
Take note this will affect access to the mailbox.