A new client side feature which Microsoft has released in Exchange 2010 SP1 is the ability of Outlook 2010 to automatically map all mailboxes to which the logged in user has full access. There by, on each mailbox that you have been granted Full Access, you will see it on your own personal mailbox. In Order to disable automatic mapping: Go to this user mailbox, right click on it and choose manage full mailbox access, then just remove your user from the full mailbox access page You can use Read more