I have a Partner ACS Rel. 7 with a 5.0 voicemail. When an extension is on the phone and receives another call the caller gets a busy. How can I make the additional call go straight to voicemail or ring and then go to voicemail. The first call will go to voicemail if it is not answered. The busy only occurs if the extension is in use. I have set Automatic VMS on all stations. Any ideas?