I have been using efax for years to receive faxes as email. I have used faxzero couple of times to send. works. I do not have a land line phone(cable only and cell). When I did have phone line I used and paid for Fax Machine software. It works great for someone who does not send or receive that many faxes.
I FOLLOWED YOUR STEPS BUT WHEN I CLICK ADVANCED THE EDIT BUTTON IS GREYED OUT