mx.hupmobiles.com has no NS records.
NS records for this zone are defined at hupmobiles.com.
NS records for this zone are defined at hupmobiles.com.
Question and response
Question
dig mx.hupmobiles.com. NS
Answer
The response has no answer records.
Authority
hupmobiles.com. 3600 SOA dns.hupmobiles.com. hostmaster.hupmobiles.com. 1921424131 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0