As long as the Exchange server you install that came with Unity is only used for voice messages you can set it up as off box or on box (preferably off box if you can).
The easiest way to do this is to install Unity on it's own network entirely with it's own Exchange server and then use DiRT to pull information off the existing Unity and restore it onto the new Unity - then uninstall the old one. All your user info should be saved (I'd leave messages off the backup to avoid issues where you card email over by accident).
As long as no one is connecting via deskto clients to the mailboxes on the Exchange server you installed for Unity to use, there are no licensing issues to worry about and you should be good to go.
If you want to leave the Unity server in the customer's directory then it gets a bit trickier since you'll have to manually create hidden mailboxes for use as Unity VM subscribers on your own...
Problem solved. My licensing issue was actually being caused by the "Cisco Unity Inbox" service that gets added to the default subscriber template after an upgrade to 4.0(3). I turned it off and my licensing problem went away.
These are the paths to get to each CCX logs through CLI. They may be helpful if you are having issues accessing RTMT or downloading logs through it.
If you want to download them you have to prefix "file get " and you can add one of the options (re...