This thread is going in two directions (One for Hardware and one for own mail) ...
With regards the mailserver I run my own, via hmailserver (
www.hmailserver.com) a windows utility that stores mail on my local machine as Exchange would for instance. I collect mail from my hosted (I-WEB) account using a utility called EFS (
www.chimeracomputing.com).
As stated above by Toto the mail will need to route via a valid server or most mailservers will bin you off as being a spammer which means you should get an alternative address (hosting) you can send from your own machine as
someone@domain.com if you have the mx records of domain.com set up to your hosted domain (which is why I use EFS to pull my mail from the server to the local server).
Give me a shout if you want any advice (as I set mine up again last night!)