I created a new user yesterday afternoon and noticed that they are not appearing in our OAB. I checked the server and noticed that the last time it was generated was yesterday at noon, at around the time we decomissioned/removed the last remaining PF database on our last 2003 back-end server. We did so gracefully and without errors as per the many guides readily available online. When I tried to manually update the PF database through EMC on our Exchange 2010 box we get the following error: Action 'Update' could not be performed on object 'Default Offline Address List'.Default Offline Address List Failed Error: Exchange server "Public Folder Database 0806651907" was not found. Please make sure you typed the name correctly. The PF database is running. My Outlook 2003 clients are not receiving errors when we hit send/receive. I'm just not able to update it with new users. We stopped and started the PF database and then restarted the server. Neither of those worked. This is the error we receive in our event log: Update-OfflineAddressBook {Identity=\Default Offline Address List} MYDOMAIN.local/Users/Administrator S-1-5-21-1451298434-3464494489-2082657383-500 S-1-5-21-1451298434-3464494489-2082657383-500 ServerRemoteHost-EMC 368 7 00:00:00.0937644 View Entire Forest: 'True', Configuration Domain Controller: 'DC1.MYDOMAIN.local', Preferred Global Catalog: 'DC2.MYDOMAIN.local', Preferred Domain Controllers: '{ DC2.MYDOMAIN.local }' Microsoft.Exchange.Configuration.Tasks.ManagementObjectNotFoundException: Exchange server "Public Folder Database 0806651907" was not found. Please make sure you typed the name correctly. at Microsoft.Exchange.Configuration.Tasks.DataAccessTask`1.GetDataObject[TObject](IIdentityParameter id, IConfigDataProvider session, ObjectId rootID, OptionalIdentityData optionalData, Nullable`1 notFoundError, Nullable`1 multipleFoundError, ExchangeErrorCategory errorCategory) at Microsoft.Exchange.Configuration.Tasks.DataAccessTask`1.GetDataObject[TObject](IIdentityParameter id, IConfigDataProvider session, ObjectId rootID, Nullable`1 notFoundError, Nullable`1 multipleFoundError) at Microsoft.Exchange.Management.SystemConfigurationTasks.UpdateOfflineAddressBook.InternalValidate() at Microsoft.Exchange.Configuration.Tasks.Task.ProcessRecord() Context Any ideas? Everything had been working wonderfully up until this point.

Fixed it! Turns out, when I decomissioned the last PF database on my 2003 server it changed the OAB generation server name on the 2010 side to the Exchange 2010 PF database name. I changed it back to the Exchange 2010 server (as it was originally) and it's working beautifully again.

Thank you for sharing the solution with us. Yes, it is recommended to use the Exchange 2010 MBX as the OAB generation server. For more referernce about the OAB related issues, I woud like to recommend the following blog: http://blogs.msdn.com/b/dgoldman/ Thanks, Simon