mail.stelin.net has no NS records.
NS records for this zone are defined at stelin.net.
NS records for this zone are defined at stelin.net.
Question and response
Question
dig mail.stelin.net. NS
Answer
The response has no answer records.
Authority
stelin.net. 600 SOA root-dns.netcup.net. dnsadmin.netcup.net. 2026021670 28800 7200 1209600 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0