This is for home use I presume? You can't really fax in and out of email directly. You either need software (i think symantec has a fax program for this purpose) or a printer that is fax capable and comes with it's own fax software. You would need a modem if you just use the software option and the printer will have it's own modem that you plug into your phone line.
Some fax software may have the option to deliver it to your inbox otherwise it would just open up a recieved fax on your desktop.