Setting up an additional email domain

RafalB

I need to setup an additional domain for my company and have never done this before. I know how to do it on the server (ms exchange 2007 (create accepted domains etc)) but currently the domain is with a third party, so what needs to happen with their side to point to my domain, and from the DNS perspective.

Also once the email domain is setup in exchange I presume it appears in the console, so I can create additional email addresses and setup the accounts.

Ha Long Bay

You will just need to create an accepted domain in Exchange and then get access to the DNS records to create a new MX record for the new domain and point it to your external IP on the server. After creating the accepted domain in Exchange you will be able to add it to the users. If you are using the default policy the mailboxes will be automatically updated.

mneylon

You'll need to create an A record pointing to your external IP (if you haven't done so already)
The A record can then be used as the MX record for the domain(s) you're setting up

You cannot use an IP address as an MX record

So for domain.tld you might create an A record for mx.domain.tld and you can set that as the MX for any domains you're using
ie. the MX record doesn't have to be on the same domain

The current registrar or hosting provider should be able to either update the MX record for you or show you how to do it
Make sure that you only have 1 MX record when you're done or the email routing will be a little unpredictable