Got an issue that I can't seem to crack here. We have an Exchange 2003 mailbox server where mailbox management refuses to run. ALL other funtionality is working correctly on the box, but whether you kick off that process manually or thru a schedule you end up with 2 errors in the event log: EventID: 9175 Source: MSExchangeSA Category: MAPI Session Details: The MAPI call 'OpenMsgStore' failed with the following error: The information store could not be opened. The logon to the Microsoft Exchange Server computer failed. MAPI 1.0 ID no: 80040111-0286-00000000 EventID: 9200 Source: MSExchangeSA Category: Mailbox Management Details: Failed to perform MAPI logon. I know about all the possible implications of the event 9175 and "80040111-0286-00000000" error, but from what I've found that doesnt seem to be applicable: Information Store (IS) is not running. IS is running, but one or more databases are not mounted. The Read System Access Control List (SACL) of Exchange Enterprise Group is lost. Inappropriate permissions on the MDBDATA folder System Attendant Service is running with a different user account than "Local System". The Default Public Store attribute on an Exchange 2000 server points to an Exchange 5.5 server public store in another domain The System Mailbox object that is created for this mailbox store exists in the Microsoft Exchange System Objects container I'm considering the idea of renaming the C:\WINDOWS\system32\mapi32.dll and replacing it with a version from our other servers, but I can't seem to see why. They're the exact same version, size, modifydate everything. The one thing about this server is that it houses some VERY high-traffic mailboxes. It used to be that mailbox management would die simply because the databases holding these mailboxes would get too large to process. Now, even on a brand new database mailbox management dies everytime. Here's the details for the server: exchange 6.5 sp2 server 2003 standard sp2 mixed mode environment Any ideas? thanks in advance! jm

run Exbpa and initiate Diagnostics logging .If things are right there may be a Hotfix . ( Hope AV settings etc are fine and store .exe is utilizing normal CPU)

In case anyone else runs into this, recreating the System Attendant mailbox resolved the issue. Even though all signs pointed to it being fine, I went ahead and rebuilt the mailbox just for giggles: http://social.technet.microsoft.com/Forums/en/exchangesvrgeneral/thread/70d6ff8d-fdc4-497e-8bf9-da88d270bef8 hope this can help someone out - thanks all! jm