I have a voicemail service from at&t when I put the auto answer on for the fax machine it will not work. Although with a answer machine it works fine. I have changed rings to more, even, and less than vioicemail without positive results. I am beginning to think at&t does this to get me to buy another phone line for fax, or I am missing something . If anyone has had this problem and can help thanks in advance.

I have an older HP fax machine which works fine on auto answer with both ans. Machine and phone company voicemail.
I recently purchased a new HP all-in-one printer and cannot use auto answer. The phone co. (not att) says I have to get a sep. number for the fax machine at a cost of about $ 5.50 per month.
So I presently have the old and new machines both hooked up. I can send on the new machine and the old one still sends and receive automatically. The technology was there with HP about 12 years ago but is not there now. I am a little suspicious too.

Because 12 years ago phones were still analog. Now they are all digital. The technology is now different.