mx.doctormatera.com has no NS records.
NS records for this zone are defined at doctormatera.com.
NS records for this zone are defined at doctormatera.com.
Question and response
Question
dig mx.doctormatera.com. NS
Answer
The response has no answer records.
Authority
doctormatera.com. 3600 SOA dns.doctormatera.com. hostmaster.doctormatera.com. 1514328043 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0