Domains and Emails

Quick Q

I have accounts linked to an email I can't access because the server doesn't exist anymore and the domain is no longer registered. It's avaliable for purchase.

Q. If I bought the domain, would I be able to recreate my old email address? Also, would those accounts already linked to the email be able to send mail to the new inbox?

PLUS can I have two domains on one server?
Thanks.

EDIT:

It used to be a Windows Live ID but for some bizzare reason it got dropped. Would I be able to recreate that ID? I assume all contacts would be gone if possible.
Thanks.