hike,
I got hylafax working using WinprintHylaFAX, a windows based client. It has a simple address book attached
HylaFSP also works as a client. It uses Windows Fax and reads the address book from outlook, so it has better integration and less quirks but it costs money.
Here's a quick how-to :-
Add a group called faxmaster and add a user to that group in server-manager.
Download these rpm's :-
libtiff-3.6.1-8.i386.rpm
sharutils-4.2.1-22.2.i386.rpm
fontconfig-2.2.3-7.i386.rpm
ttmkfdir-3.0.9-14.1.EL.i386.rpm
xorg-x11-font-utils-6.8.2-1.EL.13.20.i386.rpm
xorg-x11-libs-6.8.2-1.EL.13.20.i386.rpm
xorg-x11-Mesa-libGL-6.8.2-1.EL.13.20.i386.rpm
xorg-x11-xfs-6.8.2-1.EL.13.20.i386.rpm
VFlib2-2.25.6-25.i386.rpm
chkfontpath-1.10.0-2.i386.rpm
urw-fonts-2.2-6.1.noarch.rpm
ghostscript-7.07-33.i386.rpm
ghostscript-fonts-5.50-13.noarch.rpm
hylafax-4.2.5-1rhel4.i386.rpm
Run this script where the rpm's are.
==========CUT===============
#!/bin/sh
# Install Hylafax
/bin/rpm -ivh sharutils*rpm
/bin/rpm -ivh fontconfig*rpm
/bin/rpm -ivh ttmkfdir*rpm
/bin/rpm -ivh xorg*rpm
/bin/rpm -ivh VFlib2*rpm
/bin/rpm -ivh chkfontpath*rpm
/bin/rpm -ivh urw-fonts*rpm
/bin/rpm -ivh ghostscript*rpm
/bin/rpm -ivh hylafax*rpm
/usr/sbin/faxsetup
mkdir -p /etc/e-smith/templates-custom/etc/inittab
echo "fax:23457:respawn:/usr/sbin/faxgetty ttyS0" > /etc/e-smith/templates-custom/etc/inittab/S85hylafax
/sbin/e-smith/expand-template /etc/inittab
# Make sure HylaFAX is restarted at boot
ln -s /etc/rc.d/init.d/hylafax /etc/rc.d/rc7.d/S92hylafax
# Restart HylaFAX
/sbin/init q
/etc/rc.d/init.d/hylafax restart
echo
echo
echo "Now modify /var/spool/hylafax/etc/hosts.hfaxd to allow client access."
echo "Add the line ^.*@.*.\.yourdomainname\. to allow access from your domain."
==========CUT=============
I just noticed libtiff is in the rpm list but not in the install script????
It definately needs libtiff to work.
I've only ever done this on newly installed test machines.
There are also a couple cleanup jobs that need to be added to cron.
I haven't got that far yet

Good Luck.