No, sounds like you've got it set correctly. The *hostname* is 'mail.jzeller.com', the *domainname* is 'jzeller.com'.
At the moment Zimbra by default binds to port 80 on all IP addresses, which is the same as your webserver will do by default. There are various methods of changing this, personally I think the easiest is to change Zimbra to port 85, then use Apache proxy module to assign a vhost to proxy port 85, so you end up with Zimbra appearing to be on, eg.
http://mail.jzeller.com:80/, but it leaves
http://www.jzeller.com:80/ free for web stuff. Alternatively you can use 'zmtlsctl' to switch zimbra to ssl mode which means you would use
https://mail.jzeller.com/ for zimbra, fine if you don't have any other https sites. It's all covered comprehensively in the wiki and here in the forums.
Good luck
