Here are some quick notes on Exchange 2007 backups with Backup Exec:
Backup Exec needs unique named account for the first 5 Characters to run under. It can be administrator if you make sure no one creates an admin account with e-mail, but if you are like us it is better to just create an account that doesn’t have anything in common with your current naming convention. One way we do this is to add numbers into the first 5 characters of the BE account since no user should have that in their logon name for our clients.
BE service account needs a NON-Hidden mailbox with at least 1 message in it (verify it is created fully by sending a test e-mail to the account since Exchange will create the mailbox, but wait to make the information store information for that mailbox if it doesn’t have any e-mail in it)
Needs exchange 2007 Management tools installed on the Backup Exec Media Server if the BE Media Server is not the Exchange Server
Exchange server 2007 needs the MAPI CDO client installed
Double check permissions for the BE Service Account and verify it has the proper Exchange Group Memberships
Make sure to verify that you are able to see the individual mailboxes for restores after the first backup to verify that it is setup correctly, some early versions of BE 12 and 12.5 had problems with being able to see more than 30 mailboxes for restoring [they are on disk or tape, but not showing up in catalog to select for restoration]. If you have this problem, then verify that you have all the updates on BE since the problem has been resolved with a hotfix. If you are needing to do the restore now, then you can still use the current media, but will need to re-catalog it before it will see the “missing” mailboxes.
Here is the Symantec TechNote for Reference on the above notes: