You may have entered the Exchange Service Account incorrectly during the
upgrade. Go into Control Panel | Services and modify the login
information
on the appricable Backup Exec 7.x services. Start them and stop them.
Then
try again.

BTW, it is not necessary to backup mailboxes with the Exchange Agent.
When
you just to the regular IS/DS backup, all of the mailboxes are backed
up.
The only thing the agent lets you do is backup/restore individual
mailboxes.
I don't know how big your GAL is, but the troughput on our backups drops
to
3 megs -- it would finish in Y3K.

Hope this works out for you.

Matt

"Ross Fisher" wrote in message
news:387d374b@hronntp01....
>
> We had a site running Veritas v7.2 and completed the upgrade to v7.3.

Before
> the upgrade the system was configured to backup all the Exchange

mailboxes
> using the Exchange client, however after the upgrade we are now

getting a
> message "Unable to atach to \\TANT\Microsoft Exchange Mailboxes"
>
> Same old story, nothing else has changed!!
>
> Any answers?