1) From a command prompt type ‘nslookup’.
2) By default this will connect to the client primary DNS server if you are required to change the DNS server, type the following, where x.x.x.x is the IP address of the DNS server
3) Type ‘set type = mx’ to configure the query type to be for MX records.
5) Type in the the email domain. For Example, gmail.com
6) A list of MX records listed in the order of their preference, name server and host records details will be returned.