How can I setup my domainkey for my server? e.g. server1.example.com

I know how to setup domainkey for each hosted domain in cpanel, i.e. go to Email Authentication.

I am on a dedicated server in a different country, CentOS 5, WHM and EXIM and DNS with orbit's DNS. There are 30 domains hosted in my dedicated server.

Do I create another cpanel account for server1.example.com?