I'm also seeing an increase in notification emails after applying MP5 to our backup server.
Manual backups, scheduled policy jobs, they are all the same. We are getting 2N+1 emails where N equals the number of servers (hostnames) in the policy.
Tested a few manual jobs today to get a rundown of timestamps and what exactly the emails are. We're using client notifications, so the clients (Unix servers) send emails to one server that runs a script against incoming mails, strips out some data, and formats a single email that is sent via Exchange server to our Admins.
So far, I'm seeing two "ImmedBk" messages with no indication what policy/job it relates to and a single "backup of XXXXX completed successfully" email. So for a single server, I'm getting 3 emails.
Tried applying MP5 to the clients, since this started after applying MP5 to the backup server, but that didn't resolve the issue at all.
I've been unable to find any other info or resolution on this so far, but I'd like to know if anyone has any ideas or knows of a fix/update that will square this away. I'll certainly post back with anything I find also..
Thanks!