in Planet Linux OpenSource Debian Computing Networking Software ~ read.

Implementing fax and vbox server with capisuite and FaxGW

Capisuite is a fax and voicebox solution for capi on linux. I'm using it with a Fritz!Card 2.0 on debian.
Assuming a working capi card, you only need:

# apt-get install capisuite

Then you need to customize capisuite.conf, fax.conf and answering_machine.conf in /etc/capisuite/ and you will have a vbox and a fax recieving machine.

For sending a fax, I installed FaxGW. It provides a samba printer where you can dump your documents to fax and a webinterface to define where the documents should be send to.
Required is samba, a mysql server, php and the commandline tools tiff2ps, ps2pdf, tiff2pdf, sfftobmp, pdftotext, sed, grep. There is a german README with installation instructions included.