title: sending/receiving external email without a domain name?
body: <p>I want to install a mail server to send email and receive external email (from other server from the internet) either with sendmail or postfix in unix or hMailserver on windows. Since it's easy to setup a web server that people can access over the internet without the need of a domain name, and that works pretty much like any other web server that use a domain name. I was wondering if it is possible to setup a mail server that could also work, with IP only just like any mail server on the internet works.</p>
  
  <p>email addresses would be like:</p>
  
  <blockquote>
    <p>example@my.ip.is.here</p>
  </blockquote>
  
  <p>If it's not possible will it be possible to do so with a domain name of type A (my IP is linked to an A type domain name)?</p>
  
  <p>Thanks.</p>