sms-stop.staging.squalomail.com has no NS records.
NS records for this zone are defined at squalomail.com.
NS records for this zone are defined at squalomail.com.
Question and response
Question
dig sms-stop.staging.squalomail.com. NS
Answer
The response has no answer records.
Authority
squalomail.com. 60 SOA ns1.itars.eu. hostmaster.itars.eu. 2025111800 60 60 604800 60
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0