MX Records, Postfix, and Subdomains

[SamaelH]

Hello again!

I'm now in the process of trying to figure out my new server/domain's e-mail system. Which is to say, it doesn't have one.

Am I right to assume that, with only an IP and a registered domainname directed to it that I can recieve e-mail there, provided I install everything on my server to handle it?

Given that, I'm wondering how to go about doing this.

Postfix looks like a simple enough path, however, it often describes using addresses such as:
mail.whatever.org

The problem is that I don't have any subdomains setup, and my DNS control's ability to add them generally asks me to give a URL for it to point to (or to simply give it @, in which case it points to the server itself).

Then I encountered this thing called an MX record, and while I understand the principle, I'm still a bit lost.

Are there any tutorials out there or steps that explain how to go about setting up my server to receive and send e-mail on different addresses (bob@whatever, fred@whatever, etc), given the following?:

1) I have a server and an IP
2) It has a domain name
3) I'm an idiot who doesn't know what he's doing.

Thank you very much!

[elgato319]

mx-records:

They define which mailserver is responsible for handeling mails from this domain.