spf4.cesky-hosting.cz has no NS records.
NS records for this zone are defined at cesky-hosting.cz.
NS records for this zone are defined at cesky-hosting.cz.
Question and response
Question
dig spf4.cesky-hosting.cz. NS
Answer
The response has no answer records.
Authority
cesky-hosting.cz. 1800 SOA ns1.thinline.cz. hostmaster.cesky-hosting.cz. 1533053987 86400 300 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0