Some time after disable a mailbox and enable it again it remain disabled and in owa you can get the error : [Microsoft.Mapi.MapiExceptionMailboxDisabled]: MapiExceptionMailboxDisabled: Unable to open message store. (hr=0x80004005, ec=2412)
This issue occurs because Directory Service Access (DSAccess) caches a query for the disconnected mailbox when the mailbox is not found in Active Directory. More specifically, DSAccess caches a query that cannot find the disconnected mailbox.
To update the status of the mailbox in the current store is to run clean-mailboxDatabase :
Clean-MailboxDatabase MBD01
in exchange 2013 the command are :
This will reset the status of mailboxes in mailbox databse MBD01
Update-StoreMailboxState -Database “db_name” -Identity “mailbox_guid”
thanks