Hi Andy -
I've been on vacation and just saw this post unanswered today. Hope you've found something out before my response, but here are my thoughts anyway:
1. Was permissions wizard run on Unity for the new physical Exchange server (including the Exchange permissions that are run from the Delegation of Control wizard) for its information stores? If not, I recommend running this.
2. If Unity was partnered with the other Exchange server and it is down, Unity is missing is Unity_servername mailbox which is needed for taking voice messages from external callers. The way to fix this would be:
- Make sure #1 above has been done first.
- Move the Unity_mailbox from the old server to the new one using the Mailbox move utility. If the old Exchange server is not operational, restore the Unity_servername mailbox from backup to the new Exchange server.
- Run Message store configuration wizard, which you can do from Add/Remove programs in the Unity server's control panel. Select Change to run the program and select the new Exchange server.
Best wishes, Ginger