An MX record sets the mail server for a given domain name, directing all email to the correct location and mail server. If you have the domain myname.com, setting an MX record for myname.com will determine where mail for anyaddress@myname.com is sent. The mail server must be configured to accept mail for the domain name.

By default your domains with Green House Web Hosting will have an MX record pointing to mx.stackmail.com. You can change this if you wish to use a different mail server. To do this you need to log into your hosting control panel and select Manage DNS if that is available to you.