mx.hdomestic.com has no NS records.
NS records for this zone are defined at hdomestic.com.
NS records for this zone are defined at hdomestic.com.
Question and response
Question
dig mx.hdomestic.com. NS
Answer
The response has no answer records.
Authority
hdomestic.com. 3600 SOA dns.hdomestic.com. hostmaster.hdomestic.com. 1196780932 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0