Hello,
Please note that the 'deleted item retention' is a feature of Microsoft Exchange. But, if the retention period is over or the retension period is not specified and the customer wants to recover the deleted items in a mailbox and has a mailbox backup, he can restore the items in that particular mailbox. He need not restore the whole Information Store for the same.
When the Exchange Mailbox branch on the Backup Selection tab is selected, individual mailboxes (or the individual folders or messages within the mailboxes) can be selected for backup, and are later eligible for restore operations.
Also, you can backup and restore individual contacts or calendar appointments using Backup Exec. You need not restore the whole Information Store for the same.
Thank You,
Shweta