General hostname domain email question.

[stefanos]

Hi,

I set up a perfect server with Debian Lenny.
I am a bit confused about domain names and emails and I would like some clarification.

Say I own a domain name called corenet.com
The A & MX records all point to my IP

I have called my server with a host 'dragon'.
and thus the hostname for the server is dragon.corenet.com

If I understand an email would be linked to a hostname.
i.e. an actual email should look like: stephen@dragon.corenet.com

So if I were to send an email to 'stephen@dragon.corenet.com' it should be delivered to the user's account 'stephen' on dragon.

But what happens if I want to send an email from the outside world to stephen@corenet.com and it be delivered to 'stephen@dragon.corenet.com' does this work in a similar way to apache's ServerAlias? And how would you configure this is courier?

Should corenet.com & dragon.corenet.com both resolve from the outside world to the same server IP or should dragon.corenet.com resolve internally on my LAN only and the default for *.corenet.com resolve to the server's IP?

And what should I actually use for 'System mail name'?
1) dragon.corenet.com or
2) corenet.com

Does anyone know of a good tutorial on server host naming?

*Domain name has been changed*

If I am a bit confusing I can try and clarify but it's all Greek to me.

Kind Regards
Stephen