mms.metroport.pl has no NS records.
NS records for this zone are defined at metroport.pl.
NS records for this zone are defined at metroport.pl.
Question and response
Question
dig mms.metroport.pl. NS
Answer
The response has no answer records.
Authority
metroport.pl. 3600 SOA metroport.pl. dns.insite.pl. 2014041895 3600 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0