To check your DNS you should do 'dig yourdomainname.com any' & dig yourdomainname.com mx'
Your /etc hosts file is also incorrect, it should be like this:
Code:
127.0.0.1 localhost.localdomain localhost
192.168.1.x mail.yourserver.com mail
Obviously for the IP 192.168.1.x you would put the FQDN of your server.
There's nothing I can do about the License, if you're trying to convert to Zimbra and you need an extension then you'll need to contact Zimbra sales about the license.