smtp02.it.megacable.net.mx has no NS records.
NS records for this zone are defined at net.mx.
NS records for this zone are defined at net.mx.
Question and response
Question
dig smtp02.it.megacable.net.mx. NS
Answer
The response has no answer records.
Authority
net.mx. 1800 SOA m.mx-ns.mx. hostmaster.nic.mx. 1772838991 900 900 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0