[expert] Mail server names & MX settings

[Stephen Boulet]

Can someone tell me how to edit my MX settings for my domain registrar?
Say my firewall/web server/mail server box is named "homer", and my domain is
thesimpsons.net.

I have entries for "Host Name" and "Mail Server" that I need to fill out with
my domain registrar, and I will be using Postfix as my mail server software.

How do I fill these fields out?

-- Stephen