Install Kolab1 from zfos.org

mkdir /usr/local/kolabsrc
mkdir /usr/local/kolab
mkdir /usr/local/tmp
ln -s /usr/local/kolab /kolab # make sure there is enough space... strange error logs can happen
ln -s /usr/local/tmp /tmp # make sure /tmp provides write access to all
cd /usr/local/kolabsrc
Strange thing with ZFOS is: don't use the version from May, it seems to be an intermediate version between Kolab 1.0 and 2.0.
You would get the error in Toltec: ERROR: Unable to list the INBOX for this account. The "list" permission is not added to the INBOX on the IMAP4 server.
This would be with the May version, where there is already a binary: 
wget --recursive --timestamping --no-directories --level=1 --reject=gif,png,html,=A,=D ftp://ftp.zfos.org/brew/kolab/BIN/kolab-20040203-2.1.0/ix86-fedora2/
sh obmtool kolab
/sbin/chkconfig xinetd off
/sbin/chkconfig sendmail off
/sbin/chkconfig apache off
/sbin/chkconfig mimedefang off
/sbin/service httpd stop
/etc/rc.d/init.d/xinetd stop  # to stop imaps
/etc/init.d/sendmail stop
/etc/init.d/om-firewall stop
/etc/init.d/mimedefang stop

/kolab/etc/kolab/kolab_bootstrap -b
need to add these lines to /kolab/etc/kolab/kolab.globals
fqhostname: kolab.ict.om.org
postfix-mydomain: ict.om.org
/kolab/sbin/kolabconf
/kolab/etc/rc all start
/kolab/bin/cyradm -user firstname.lastname@my.mail.domain.org localhost
createmailbox INBOX
see also http://kolab.org/pipermail/kolab-devel/2004-August/001723.html

firewall as described earlier, just replace ipchains with /sbin/iptables

disable postfix: 
rm /kolab/etc/rc.d/rc.postfix

This is direct from the sources: 
wget --recursive --timestamping --no-directories --level=1 --reject=gif,png,html,=A,=D ftp://ftp.zfos.org/brew/kolab/SRC/kolab-20040217-2.0.0/
That gives me trouble when compiling gcc-3.3.3-2.0.0.src.rpm, internal compiler error: Segmentation fault