Can anyone point me in the right direction to resolve both errors? I've checked on sites like eventid.net but the listed solution to replace the mapi32.dll with one from a backup has not worked. I have verified the stores are both mounted (public folder store & mailbox store). Even the services needed for Exchange have been started, even cycled them a few times with no effect. Everything else seems to be running fine but I am receiving the ID 9175 every minute or so. With this error I am not able to backup the mailboxes. Thanks Event Type:ErrorEvent Source:MSExchangeSAEvent Category:MAPI Session Event ID:9175Date:5/29/2008Time:10:20:06 AMUser:N/AComputer:Servername Description: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 StoreID no: 8004011d-0512-00000000 For more information, click http://www.microsoft.com/contentredirect.asp. Event Type:ErrorEvent Source:MSExchangeFBPublishEvent Category:General Event ID:8197Date:5/29/2008Time:10:09:31 AMUser:N/AComputer:servernameDescription:Error initializing session for virtual machine DG-DC3. The error number is 0x8004011d. Make sure Microsoft Exchange Store is running. For more information, click http://www.microsoft.com/contentredirect.asp.

In your researching this, have you seen Microsoft's Event and Errors Message Center? http://www.microsoft.com/technet/support/ee/ee_advanced.aspx A quick search there may help....? http://www.microsoft.com/technet/support/ee/transform.aspx?ProdName=Exchange&ProdVer=6.5.6940.0&EvtID=9175&EvtSrc=MSExchangeSA&LCID=1033 http://www.microsoft.com/technet/support/ee/transform.aspx?ProdName=Exchange&ProdVer=6.5.7596.0&EvtID=8197&EvtSrc=MSExchangeFBPublish&LCID=1033

I would like to add, that working with B_Hill78 on this issue, checking the registry for the ExchangeAdmin <server name> <GUID> key to verify the correct GC is being accessed. These keys are missing, and there are a ton of random alpha-numerickeys under the HKEY_USERS\.DEFAULT\Software\Microsoft\Windows NT\CurrentVersion\Windows Messaging Subsystem\Profiles\ExchangeAdmin<server name><GUID>, with 6-8 subkeys in which there is once subkey in these sets that has an entry about the REstrospect backup user mailbox. Theseramdon alpha-numeric subkeys are what youwould see under the ExchangeAdmin main key. The whole issue is that the stores are running, but with the ExchangeAdmin main keys missing Retrospect backup is unable to backup the individual mailboxes.

Both event ID's have been resolved 1) I was directed to erase the value of "Disable MAPI client" key in registry under: Hkey Local\system\currentcontrolset\services\MsExchangeIS\ParametersSystem\Disable MAPI client modify then delete the value, mine WAS 6.7638.2 then ok and close out regedit 2)From exchange sys manager expand until you get to the server name, right click then select properties. Diagnostic logging tab -> selectMS ExchangeIS -> Select OAL... change from Maximum to NONE. Ok to save. 3) Restart Exchange system attendant. Hope this helps someone in the future..