[Mailman-Users] Mailman DNS Issues

I recently installed mailman on a new Ubuntu server. The setup went through without a hitch ... Or so I thought.

When I try to log into my installation of mailman using a browser: http://www.myhostname.com/cgi-bin/mailman/admin, there is a 404 error page.

However, when I go to http://myipaddress/cgi-bin/mailman/admin It works fine.

Is this a DNS issue?

The only error message I get when starting my server is the following:

NameVirtualHost myipaddress has no VirtualHosts mailman