mx.hardkeep.com has no NS records.
NS records for this zone are defined at hardkeep.com.
NS records for this zone are defined at hardkeep.com.
Question and response
Question
dig mx.hardkeep.com. NS
Answer
The response has no answer records.
Authority
hardkeep.com. 3600 SOA dns.hardkeep.com. hostmaster.hardkeep.com. 1971502595 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0