For the full configuration sequence, see the OS X Server 10.6.8 Getting Started and related manuals.
The first two steps I use involve getting the IP network configured and going and ensuring that your server's DNS services are configured correctly and started.
DNS services are not optional. That service needs to be functional for at least the server's own local needs, and (once that's working locally, there's little reason not to set up DNS for the rest of the NAT'd network), or all sorts of other stuff goes weird.
From out here in the internet boondocks, server.sudarja.com is a CNAME, which usually means that DNS is incorrectly configured somewhere. Should you get around to SMTP, a CNAME will definitely blow up. In general, the server needs a DNS A (machine) record. It can then have zero or more CNAMEs.
To test your local DNS directly on your server, launch Terminal.app from Applications > Utilities and enter the following (diagnostic, no changes are made) command:
sudo changeip -checkhostname
The sudo there will prompt for your administrative password, and the command will then check and show you some details and whether local DNS is correct and no changes are required, or if there are DNS or network errors and changes are required.