We have the Mitel 3300 box. I have one phone that seems to be acting up on me. Mitel 5312. When I select forward to VM from the phone the voicemail picks up. When I cancel the forward and no one picks up the phone when dialed the voicemail never picks up. After about 12 rings the phone stops ringing at the desk and goes back to the receptionist. I have looked at every setting on the box, I cannot find why this phone is acting differently than all of our other phones equipped with Voicemail.