Backup Exec uses Microsoft Exchange Web Services (EWS) to support the Granular Recovery Technology option. EWS provides support for the restore of individual mailboxes, mail messages, and public folders from an Exchange Server 2010 database backup.
To use EWS to restore individual items, Backup Exec disables the client throttling policy for the resource credentials you specify for the restore job. The client throttling policy is located on the Client Access Server and enforces connection bandwidth limits on the Exchange server.
Backup Exec also creates an impersonation role and a role assignment for Exchange Impersonation. Exchange Impersonation role assignment associates the impersonation role with the Backup Exec resource credentials you specify for the restore job.