Is the faxaway service for free? How can one use it to send faxes from
emails?
Nothing in life is free... :)
The closest thing to free is probably HylaFAX, which I've been using
successfully for a couple of years now. I have mine set up for use
in three ways:
a) print to it as if it was a printer
b) use an authenticating Web form to upload postscript files and fax them out
c) use an email interface that accepts a PGP-signed message containing
a postscript message (done via procmail -- checks signature, pulls out
phone number from header, dials and sends body)
To use HylaFAX, you'll need a fax modem, some patience, and a phone line.
The software is free to use, and can be downloaded from
http://www.vix.com/hylafax/
Chris