Hi,
As per my understanding CMM is not forwarding the voicemail messages, which were left from an external caller whose caller ID is not there or masked.
If that is the case, this seems to be a bug on CMM. I am working on a similar senario for another customer. Pls give us couple of more days to get the confirmation from the devlopment team on this matter.
Jeas Mathew|UC-Backbone|Avaya Client Services|Office: +1 720 444 1508|
E-mail: mathew@avaya.com