mx.wwwtnt.com has no NS records.
NS records for this zone are defined at wwwtnt.com.
NS records for this zone are defined at wwwtnt.com.
Question and response
Question
dig mx.wwwtnt.com. NS
Answer
The response has no answer records.
Authority
wwwtnt.com. 3600 SOA dns.wwwtnt.com. hostmaster.wwwtnt.com. 1620059076 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0