mx.runity.Ru has no CNAME records.
Question and response
Question
dig mx.runity.Ru. NS
Answer
The response has no answer records.
Authority
runity.Ru. 365 SOA cdnsa.nic.Ru. noc-dns.nic.Ru. 2026022501 14400 3600 2592000 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0