If your Mac can send a fax, it can receive one, too. Make sure that you have an available phone line, and your computer is awake. A Mac in sleep mode cannot receive a fax. Then follow these steps to send a fax from your Mac:
From System Preferences, choose Print & Fax and then click the Open Fax Queue button.
If your fax number is not shown, enter it.
Click Receive Options and select the Receive Faxes on This Computer option. Then designate the number of rings before the fax is answered.
Make sure that your Mac will pick up the fax before an answering machine connected to the same phone line.
Choose how you want the incoming fax to be treated.
You can save the fax as a PDF in the Shared Faxes folder that Apple suggests or save it to another folder; send the fax to a specific e-mail address; or automatically print the fax.
You can accept an incoming fax even if you haven’t bothered to set up the system to receive faxes automatically. Go to System Preferences, choose Print & Fax, and when your fax machine is highlighted in the list to the left of the window, select the Show Fax Status in Menu Bar option. When the phone rings, click the Fax Status icon in the menu bar and choose Answer Now.