In Exchange 2010 Service Pack 1 (SP1) Exchange introduced a feature that allows Outlook 2007 and Outlook 2010 clients to automatically map to any mailbox to which a user has Full Access permissions. If a user is granted Full Access permissions to another user’s mailbox or to a shared mailbox, Outlook automatically loads all mailboxes to which the user has full access.
This is a great time saver for help-desks, as in the past they had to constantly advise users how to add additional mailboxes to their profiles.
However, if you do have full access to a large number of shared / team mailboxes, this can cause performance issues with Outlook, especially during boot up.
In Exchange 2010 SP1, there was no way to turn this feature off. However, in Exchange 2010 SP2, you can use the Shell to disable this feature:Add-MailboxPermission -Identity BillG -User ‘Ali Butt’ -AccessRight FullAccess -InheritanceType All -Automapping $false
This example grants me full access permission to BillG mailbox and disables the auto-mapping feature.