Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
Has this HP machine worked, as a fax, previously, on this same line and phone service?
To check whether the line could be the problem: unhook the phone cable from the back of the HP machine. Then connect it to a common voice phone handset, lift the receiver, and check for the following in this order:
A. Dial tone?
B. When you dial, do you hear tones on the line?
C. When you have dialed a number, do you hear the other end ringing?
D. Does the other end answer/respond?
E. Can you - essentially - complete the call, being heard and hearing the other end ? (call your own phone e.g. your cell phone, this way, to be quite sure, and to offend no-one.)
If any one of A-B-C-D & E does not work or does not completely work, then your problem is most likely a matter for the phone co. to address, or whatever phone service provider you have (if a digital phone service or VoIP or Vonage or MagicJack, please mention this - digital phone service is quite different.)
I note that the HP device is 'new' - has it ever done a fax Send before, successfully?
If you do have a digital phone service, you may have to change a setting - that of 'ECM' or 'Error Correction Mode' - in your HP device's fax settings. That would need to be turned Off, or Disabled, in order to make working with a digital line more likely.
What was the result of the HP Fax Test? did you get a Received Reply fax back from HP ? That sound be tried. If you simply cannot send to one number, or two, then try other numbers, including the HP Fax Test #. (If you need details of the HP Fax Test # ***** procedure, let me know, and I will instruct you further.)
One thing is sure: if you can receive faxes on the line with this machine, that's good. It's promising of being able to get the sending working too. But let me know how it is going and how it goes, and I will advise you further as necessary.