mailhost.kyivlink.com has no CNAME records.
Question and response
Question
dig mailhost.kyivlink.com. NS
Answer
The response has no answer records.
Authority
kyivlink.com. 1572 SOA amalia.ns.cloudflare.com. dns.cloudflare.com. 2398294792 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0