You can restore individual mailboxes, messages, and public folders from backups that were created by the following legacy methods:
Following are notes about restoring mailboxes or public folders from legacy backup methods:
If you restore mailboxes from a backup created with a version of Backup Exec prior to 8.5, and mailboxes with duplicate Display Names reside on the server, select those mailboxes for restore separately and redirect the restore.
The option Restore Over Existing Files in the Advanced Restore Job Properties does not apply to mailboxes or public folders. If other selections are restored in addition to mailboxes or public folders, and the option Restore Over Existing Files is selected, it applies only to the other selections; mailboxes and public folders are not restored over existing objects.
The following are common examples of special system mailboxes, but there may be others depending on the Exchange server configuration and environment.