Is CXN integrated with SCCP or SIP? What version?
What does CXN say the alternate destination state is: on or off? It should show you this on the Edit > MWI page under the mailbox.
If SCCP are you able to dial the MWI Off DN from the phone? If yes does it stay off then?
If SIP is the Partition of those DNs included in the Incoming CSS of the SIP Trunk from CXN?
Please remember to rate helpful responses and identify helpful or correct answers.