How can I forward busy no answer a phone on this system? I have 2 phones that just ring when called. It is attached to a Active Voice voicemail system. Also, I have 1 phone that is getting delayed rings from line 1. This same phone is one that will not forward on the busy or no answer.

Check and see if you have this phone in cover group 30. Print ext. information on this phone and make sure cover inside is on and not off.