Before I signed up with Onesuite Fax, I checked other online fax services including efax and I can't remember you can receive faxes for free from efax aside from their 1 month fee trial (which you can receive limited faxes only)EFax is great for receiving faxes for free. They will give you a number (or at least used to) and you can get all the faxes you want at no charge. They will only charge you if you want a specific Fax # in your area, or want to send faxes. It has been working great for me for years.
If you only fax once or twice a day there is a great FREE internet based fax, called FaxZero. You can send up to two faxes per day at no charge and attach pdf files if you like. It;s a bit restrictive, but works great for me as I have no fax machine, no scanner.
Best of Luck