We have a CallManager 4.0 cluster with two sepeate Unity voicemail servers.
I setup one person on the second voicemail profile for some testing and ran into a problem.
When you call the user's phone, it forwards to their voicemail properly and the MWI appears to come on.
However, when the user presses the "Messages" button on their phone it doesn't take them to their mailbox. Instead it takes them to the general prompt where they would have to press * and login manually as if they were calling from the outside. They are able to do this, but I don't understand why Unity isn't immediately prompting them for a password.
Are you sure that 2nd-Unity user is using the pilot for the 2nd-Unity server? The fact that you are able to leave a vm for him suggest that you have forwarded the phone to the correct unity server.
Your symptom suggest that he connected to 1st-Unity server's pilot, and therefore his extn is not recognized as a subscriber; as such he gets opening greeting instead.
Yes the user is going to the appropriate Unity when he presses the messages button. 2820 is the Pilot number of the second unity and that is what is displayed when he calls.
You'll need to set up a call route to point to the Attempt Sign-In when that person calls in to the Unity box.
Go to the unity box and run Call Viewer. Have them dial in the way they want and watch the call come in. Then, take that info and create a Call Route and you should be fine.