[Techtalk] Mail Hosting

[Figaro]

Hello all.
I was going to attempt to setup a mailserver to be able to quit using
the not very well filtered services from my cable co.
I thought to use postfix-dovecot-mysql (>
http://workaround.org/articles/ispmail-etch/


So, one purchased/registered a domain name with idotz.net with dns but
suddenly realized that I have NO clue how to get my system modified to
used the domain name and dns.
This is a Debian -Sid installation that has been setup and running for
2-3 years (first with dial-up, then dhcp for the cable modem) without a
real qualified domain name (stand alone work station).
(1): I have the registered domain name
(2): I have the purchased dns management login: with provided primary
and secondary servers: BUT do not know what to do with it!
(3): I have a dynamic DNS account with dnsexit.com and an ipUpdate
daemon running for use to keep the domain name active as my cable ip
address changes. Again not any good idea how to use it correctly.

My questions:
Does anyone know of a good tutorial or set of, that one may work through
to understand the requirements to get this set up?
OR
Suggestions for a well run mail hosting service running Linux (pref.
Debian) that I may purchase to host my mail with my domain name? I
honestly do not need the ability to handle more than 3 mailboxes.

Thank you,
matthew