How to activate or deactivate a user’s voicemail?
PBX Control panel
You can enable or disable a user's voicemail under Settings > Find me. This section can also be accessed from Users, press Edit button of the user you want to edit > Reach Me. For the latter you will need to log in with an administrator user.
There you can also enter a voicemail PIN which you will be prompted to enter when dialling *0.