How to verify Mail exchange records(MX) of DNS configuration

This is a short note explaining how to verify your MX records configurations are correct or not using 'nslookup'

C:\Users>nslookup
Default Server: UnKnown
Address: 2a02:2788:fff0:7::3

set q=mx
example.com.
Server: UnKnown
Address: 2a02:2788:fff0:7::3

Non-authoritative answer:
example.com MX preference = 0, mail exchanger = (root)

example.com nameserver = a.iana-servers.net
example.com nameserver = b.iana-servers.net
a.iana-servers.net AAAA IPv6 address = 2001:500:8f::53
b.iana-servers.net AAAA IPv6 address = 2001:500:8d::53
a.iana-servers.net internet address = 199.43.135.53

hope this helps.