I have CCM 5.0 with CUM version 5 as well. I have configured a SIP trunk between the call Manager and the unity. Everything is working well but when unity dials a user to his home phone number for message notification the DTMF does not work. What ever the user enters the unit does not interpret the digits. The CCM 5.0 has the PSTN router configured using H.323.
I have followed the procedure in the below link but still it does work:
Any ides are appreciated,