This package turns your computer into a fax machine. With a Zyxel modem, you can even use your computer as an answering machine.
mgetty recognizes what kind of call it is receiving and does everything else automatically. You will find the documentation under /usr/doc/mgetty and TeX-Info files under /usr/info.
The configuration files are in /usr/lib/mgetty+sendfax and /etc/mgetty+sendfax.