I have unity connection voice mail and this works fine.
Question: is it possible to access voice mail remotly? Meaning calling my mail box and listen to the voice mail?
Yes, this should be possible. You will have to configure your PBX (CallManager) such that it can fwd calls for a DID to Unity Connection Pilot Point. Once this is done, you should hear the opening greeting. When you hit '*' at the Opening Greeting it would ask you for your Extension and Phone Password and let you listen to your VoiceMail. Also, if the Remote Phone that the caller would use would be constant (Assuming Mobile Phone/Home Phone), the DID for this phone can be configured as alternative extension and when the calls dials in to Unity, they should get the Subscriber Sign-In option the same way as they would when calling from their Work Phone