mailing.smcdn.pl has no NS records.
NS records for this zone are defined at smcdn.pl.
NS records for this zone are defined at smcdn.pl.
Question and response
Question
dig mailing.smcdn.pl. NS
Answer
The response has no answer records.
Authority
smcdn.pl. 1800 SOA cloe.ns.cloudflare.com. dns.cloudflare.com. 2398737789 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0