It's basically free bash shell script available from: http://wpkg.org/email2fax/index.php/Main_Page
Make sure you have the required tools:
libtiff
ghostscript
mpack/munpack
Where you can e-mail your Asterisk box and it will fax it to the phone number in the subject line. The good news ends there, it is fairly undocumented and buggy.
Take for example how the documentation mentions you can invoke from the com........