Technically, Dirt is your best option as it will only backup what is necessary to restore. Other backup software may function on a Unity server, but may not have TAC support. Your best bet is to use Dirt to get a full Unity backup, and not try and fo...
Another way of doing this is to go into Exchange (if you are using that) and there are settings to allow messages to be sent to multiple subscribers. Not a Unity fix, but in fact it allows you to fix the problem.
Try checking the message lengths of the Default Subscriber settings. As the users of Unity are all Default Subscribers, they pull their Class of Service from the COS settings within the default settings. I have seen a number of problems where users h...
