ns.kes.ru has no MX records.
Question and response
Question
dig ns.kes.ru. MX
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