mx1.mail6.freehost.com.ua has no NS records.
NS records for this zone are defined at freehost.com.ua.
NS records for this zone are defined at freehost.com.ua.
Question and response
Question
dig mx1.mail6.freehost.com.ua. NS
Answer
The response has no answer records.
Authority
freehost.com.ua. 1836 SOA alpha.freehost.com.ua. domainmaster.dns82.net. 2019112701 14400 600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0