Furthermore, these are not email servers, they are simply email addresses like your own, yourname07_at_yahoo_dot_com. When you register a domain, the domain registrar, for example, GoDaddy, will usually give you a couple of email accounts to name so you can have a webmaster, support, contact address and so on. No programming necessary.
Originally posted by omi sharma: I thought they have their own mail servers.Anyways ,I would like to create one in Java.
They can have their own mail servers, and many organizations do. I just wanted to make sure you understood one doesn't have to write their own server just to get a couple of email aliases. Best of luck in your endeavor.