mail.imena.com.ua has no NS records.
NS records for this zone are defined at imena.com.ua.
NS records for this zone are defined at imena.com.ua.
Question and response
Question
dig mail.imena.com.ua. NS
Answer
The response has no answer records.
Authority
imena.com.ua. 3600 SOA nsa4.srv53.net. support.dnshosting.org. 1735564459 1800 600 2419200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0