That's okay.
The problem is with your hosts file as it indicates.
When it comes to name resolution (resolving Name addresses [eg google.com] to ip addresses[192.168.0.1]), you hosts file is read before your computer will check your nameservers. Name servers are alot like the internet's phonebook.
>[prompt]tail /etc/hosts
should show you enough of the hosts file to post. Basically, you need 2 entries in your hosts file:
127.0.0.1 localhost.localdomain localhost
[ip of adapter] hostname.domain.com hostname
Now, DNS isn't really all that complicated...but i suppose it can be
Before you dive into an install that is almost destined to be filled with DNS errors, consider the following:
Do you host your own DNS, or do you have access to be able to add records to your service providers DNS?
If YES, then, you need to make sure that you add/have a type=A record pointing to your machine. Make sure you have a record in your nameserver as well. You also need an MX record (Mail Exchanger) pointing to the machine.
If you are behind a firewall, or have SE Linux installed, it will help to turn those off to avoid errors (the linux machine can handle its own).
I encorage you not to give up. This could be a great chance to be able to learn about DNS and Linux.
Now, if you do not have a static IP, then it's probably a good idea to not set up a mail server. You're gonna have a lot of problems.
Good luck, and let us know. We're here to help!
