smtp.celestemail.com has no NS records.
NS records for this zone are defined at celestemail.com.
NS records for this zone are defined at celestemail.com.
Question and response
Question
dig smtp.celestemail.com. NS
Answer
The response has no answer records.
Authority
celestemail.com. 3600 SOA ns1.celeste.fr.celestemail.com. support.celeste.fr. 2024100301 3600 900 604800 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0