mail.hitrost.com has no NS records.
NS records for this zone are defined at hitrost.com.
NS records for this zone are defined at hitrost.com.
Question and response
Question
dig mail.hitrost.com. NS
Answer
The response has no answer records.
Authority
hitrost.com. 21600 SOA dns1.hitrost.net. hostmaster.hitrost.com. 2024092602 7200 3600 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0