mta02.cmail.cloud has no NS records.
NS records for this zone are defined at cmail.cloud.
NS records for this zone are defined at cmail.cloud.
Question and response
Question
dig mta02.cmail.cloud. NS
Answer
The response has no answer records.
Authority
cmail.cloud. 300 SOA ns1-03.azure-dns.com. azuredns-hostmaster.microsoft.com. 1 3600 300 2419200 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0