
It seems clear that Microsoft is steadily moving toward using the MRS as the fulcrum for mailbox maintenance operations. In this instance, you create an import request with the New-MailboxImportRequestcmdlet to instruct MRS to access data in a PST located in a file share and import the data into a target mailbox. Much the same approach is taken for mailbox import requests. With SP1 you can run the New-Mailbo圎xportRequestcmdlet to create a request for the Mailbox Replication Service (MRS) running on a Client Access Server (CAS) to export data from a mailbox to a PST located in a file share that is protected from prying eyes by the Exchange Trusted Subsystem security group.

Exchange 2010 SP1 introduces a new cmdlet set to handle mailbox export requests to avoid the previous requirement to install Outlook on mailbox servers.
