mx01.myconvento.com has no NS records.
NS records for this zone are defined at myconvento.com.
NS records for this zone are defined at myconvento.com.
Question and response
Question
dig mx01.myconvento.com. NS
Answer
The response has no answer records.
Authority
myconvento.com. 300 SOA x.ns.joker.com. hostmaster.joker.com. 2025121049 14400 3600 1209600 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0