During an Exchange 2003 – 2010 transition, when moving a mailbox you see the database gives an “Object not found” message.
If you continue the mailbox move will fail with the following error: “Mailbox database “Servername\First Storage Group\Mailbox Store (SERVERNAME)” doesn’t exist.”
Probably you would also see some Event ID 3113, MSExchangeIS errors in your Application log indicating the Mailbox of Public Folder Store was not found in the directory. The item may have been deleted.
Solution: The problem is caused because the “Allow inheritable permissions from the parent to propagate to this object and all child objects. Include these with entries explicitly defined here.” is not set on the Exchange 2003 server object.
Open Exchange System Manager, browse to Administrative Groups, first administrative group, Servers and choose properties on your Server. Select the Security tab and choose advanced. Place a check at “Allow inheritable permissions from the parent to propagate to this object and all child objects. Include these with entries explicitly defined here.” and select OK.
If you cannot see the security tab you need create the ShowSecurityPage registry key. Open regedit browse to HKEY_Current_user\Software\Microsoft\Exchange\EXAdmin and create a new DWORD value ShowSecurityPage and set the value data to 1. Now restart Exchange system manager and you should be able to see the security page.