mail.KES.RU has no NS records.
NS records for this zone are defined at KES.RU.
NS records for this zone are defined at KES.RU.
Question and response
Question
dig mail.KES.RU. NS
Answer
The response has no answer records.
Authority
KES.RU. 86400 SOA ns.KES.RU. geo.ns.KES.RU. 2023081202 28880 7200 1814400 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0