I've had the error message below turn up on multiple occasions in the past two weeks. Staff members will complain that they lose access to Microsoft Exchange. After verifying that the server is still up and running, I hit the event log and find the error below.
The MAPI call 'OpenMsgStore' failed with the following error: The attempt to log on to the Microsoft Exchange Server computer has failed. The MAPI provider failed. Microsoft Exchange Server Information Store ID no: 8004011d-0512-00000000
The short-term resolution to this has been simple. Restarting the Microsoft Exchange Information Store service resolves the issue pretty much straight away.
However the problem keeps coming up, and I'm at a bit of a loss as to why. It's starting to feel like I'm chasing a symptom rather than treating the disease.
I know very little about Microsoft Exchange, so any indication towards the right direction would be very much appreciated.
Our version of Exchange is 6.5.7638.1, and is running on Microsoft Windows Server 2003 R2 Standard Edition.