Using our installer, btw., does not mean that you'll have to install a graphical display onto your server. The only thing you'll need on there are the X11 libraries and the Python GTK toolkit.
What I usually do is that I have CygwinX (
www.cygwin.com, it's free) running on a Windows client, then connect to the server through ssh and X tunneling (ssh -X...) and run the Installer from there. I would never install a full desktop on a server.
Also, the next release of Scalix will have an improved Installer that you can run in non-graphical mode (i.e. the prompts will all be text-based and run on a normal console). The manual installation instructions that can be found in Enterprise Edition today will then be deprecated as we don't want to update them with the growing number of little steps (with every release) the Installer goes through for the installation.
Hope this helps,
Florian.