What is an MX host?
An MX host is a mail server (SMTP server), a computer permanently connected to the Internet with a fixed IP address configured to manage email for one (or more) domain names. If you have got an own MX host and want to use it instead of managing email through Domainnameshop, choose this by checking the box top of the email administration page. You must enter the server host name (IP address will not work!) and a priority value (e.g. 10).