Need HP Printer Fax help

I just left the house of a lady that I set up a wireless printer / fax machine/ scanner and the Fax part of the printer is the only thing not working completely.

I ran multiple tests using the printers built in fax test and every time it says everything is working perfectly.

I sent test faxes to someone while talking to them on their cellphone and can hear the phone ringing on their end and can hear their answering machine through the fax, had them try it with the answering machine taken off and it still will not send and either shows busy or no answer and never goes through.

The first couple trys it was unable to receive the fax from this other person but after awhile it worked and could receive them every time. But still can not send them.

I tried different phone cables, tried using a dsl filter, changed the speed of the fax machine between medium high and low, tried different formats of the fax phone number.

Not sure what else I can do, only thing that I could think is that the other persons fax machine isn't set to auto pickup even though they claim it is.

 

Who faxes anymore can't she just email. I don't know what could be wrong, but you should post this in HP support forums. http://www8.hp.com/us/en/supportforums.html
There's people who work for HP that post there, and I've had good experiences there.

 

Tried again today and the fax machine works with every other number other than the first guy we kept trying.

 

Just went to the guys house and found out that the fax machines auto answer was turned off and the amount of rings were set to high so the answering machine messed with it because of that. Got it all fixed