1. Efax is a small ANSI C/POSIX program that sends and receives faxes usingany Class 1, 2 or 2.0 fax modem. You need to install efax if you want to send faxes and you have a Class 1, 2 or 2.0 fax modem. From Mandrake 9.0 RPM

2. Programs to send and receive fax messages. efax is a small ANSI C/POSIX program that provides the data transport function for fax applications using any Class 1 or Class 2 fax modem. Another program, efix, converts between fax, text, bit-map and gray-scale formats. fax, a shell script, provides a simple user interface to the efax and efix programs. It allows you to send text or Postscript files as faxes and receive, print or preview received faxes. The ghostscript package is needed to fax Postscript files, and a image viewing program as xloadimage is need to view incoming faxes. Note that you probably have to adapt /etc/efax.rc to your needs. From Debian 3.0r0 APT