Granular Recovery (GRE) for Microsoft Exchange is a two-phase approach today. Before the user can restore individual items from a backup a restore of a mailbox database must be performed. This is time consuming esecpailly for larger mailbox databases and if multiple restores are required to find the right point in time containing the missing elemets.
Please deliver a Cached Exchange GRE, similar to Cached VMware GRE, to eliminate the time consuming restore of the mailbox database, if the backup resides on StoreOnce (and/or DataDomain).
Very fast restores of single items from Exchange backups which allow overall better restore SLAs.