They say there's no such thing as a free meal and the same goes for faxing on the Net. You can't send faxes for free because you always need a faxing account to send them - but the interface you use can be free.
That's exactly what Fossi offers - a free faxing interface which links you to several major faxing services so you can send faxes from your Mac. For those Mac owners that do have a modem inside - that's about every pre-Intel Mac - this linking to online fax accounts is essential because otherwise you have no way of sending them. Those Mac owners that have a modem inside can simply use their existing one to send faxes.
Fossi is extremely simple to use and is divided into two tabs - General and Accounts. In the General tab, you only have to enter the prefix of the country you are sending the fax to. General is where you do all of your composing including entering the number. In the General tab, by clicking on the plus or minus symbol, you can add online faxing accounts to associate with Fossi such as eFax or Sipgate. If you don't want to use the online services, you can configure it to use your own modem if you have one.
Why pay more for a fancy faxing interface when Fossi offers it you all for free and links you to many major fax accounts?