I suppose the I was following the wrong how-to;
The Perfect Server - OpenSUSE 12.2 x86_64 (Apache2, Dovecot, ISPConfig 3)
Would following How-to be relevant for my use? I expect running commands to setup Virtual Hosting and email accounts.
Virtual Users And Domains With Postfix, Courier, MySQL And SquirrelMail (Ubuntu 12.10)
It would be quite easy for me installing another server. I'm running KVM on this PC.