Backing up Exchange mailboxes is a common cause of problems, but do you need to do them?
In versions of Backup Exec prior to 11d, Exchange maibox backups are done using MAPI, where Backup Exec effectively logs on to the Exchange server as a user who has rights to all mailboxes. This requires some initial setup, but the main gripe is that it's very slow.
In Backup Exec 11d, GRT (granular restore technology) was added for mailbox backups. This is is much faster than using MAPI (which is still available as "Legacy" mode), but has other problems (such as using up all your disk space).
So if there are so many problems with mailbox backups, do you really need them?
If you are just backing up your Exchange server for disaster recovery purposes (i.e. you just want it back if you lose the entire server), then an Exchange Information Store backup is all you need. In the event of disaster you recover your server, then recover the information store. Job done, and your backups will complete nice and quickly, as information store backups are fast.
You might want to run Exchange mailbox backups to recover items that users have deleted. However, Exchange has a feature called Deleted Items Retention. This means that when users delete an item from their mailbox, it is retained in the background for a period you define. In addition, you can select to have the item retained until a backup is run. Additionally you can retain the mailboxes of deleted users.
There are downsides to these options in that your information store will grow in size, but that may be outweighed by the benefits of faster backups and less administrator intervention. You may decide that you still need mailbox backups, but if this article makes you decide you don't need them, it may save you a lot of hassle.