mx.dtmtaxi.com has no NS records.
NS records for this zone are defined at dtmtaxi.com.
NS records for this zone are defined at dtmtaxi.com.
Question and response
Question
dig mx.dtmtaxi.com. NS
Answer
The response has no answer records.
Authority
dtmtaxi.com. 3600 SOA dns.dtmtaxi.com. hostmaster.dtmtaxi.com. 1530076724 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0