Ai bit xa`i Windows Live Custom Domains

Sao lúc mình đăng ký sử dụng windows live customs domain thì nó thông báo như sau:
if you want Microsoft to host the e-mail service for your domain, set up your DNS to send incoming mail to this service. Once you do this, you can create and manage e-mail accounts in your domain. To test your DNS configuration and update this page, click Update Now.
We last observed your MX records to be:

* No MX Records were found
To complete setup, you need to make the DNS changes listed below. You can do this at the registrar where you registered your domain or at your DNS provider.

cái MX Records là cai gì dzậy ai bit hong
Xin chỉ giáo!!!!!!