What's the use of configuring a Voice Mail profile in Call Manager?
Just to add a note to the good tip from Jaime. You can also use the Voicemail Profile to mask numbers that are routed to Voicemail and that you want to go to a specific VM Box.
There are a number of phones (5533,5522,5511 and 5544) in the Sales department but you want them all to route to the same VM Box @ DN 5000.
Create a VM Profile called "Sales" with a Vm Mask of 5000. On each of the four phones (5533,5522,5511 and 5544)on the Directory Number Configuration page for each.
Directory Number Settings
Voice Mail Profile = Sales
All calls that route to VM from the four numbers will receive the VM treatment for the 5000 Mailbox. We use this to route calls for certain Instructors to Department Mailboxes rather than having their own :)
Hope this helps!