bmail.btactic.com has no NS records.
NS records for this zone are defined at btactic.com.
NS records for this zone are defined at btactic.com.
Question and response
Question
dig bmail.btactic.com. NS
Answer
The response has no answer records.
Authority
btactic.com. 86400 SOA dns16.ovh.net. tech.ovh.net. 2025032500 86400 3600 3600000 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0