spf.mx.tsunami.pl has no NS records.
NS records for this zone are defined at tsunami.pl.
NS records for this zone are defined at tsunami.pl.
Question and response
Question
dig spf.mx.tsunami.pl. NS
Answer
The response has no answer records.
Authority
tsunami.pl. 1800 SOA devin.ns.cloudflare.com. dns.cloudflare.com. 2397832559 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0