How can I set up a user's voicemails to forward to another workgroup or user? That's either for voicemails they already own OR for new incoming voicemails.
Alternatively, can an administrator (or user) reassign them. (For most of our users we had actually set up a workgroup, like x[User Name]. In those cases I just set their workgroup to overflow. Unfortunately, not all of our users got set up that way.)
There's no way to forward a users personal voice mail.
The solution you mentioned works - creating a work group for each agent and using over flow. Why don't you do that for the all the agents? That could get out of had if yo had a lot of agents.
The best solution, if possible, is not to use personal voice mail but to use group voice mail. If it really is a situation where another person could handle the voice mail.
Another solution would be to train agents to update their voice mail message before they leave to let callers know they are gone.