mx-ys.ktcloud.com has no CNAME records.
Question and response
Question
dig mx-ys.ktcloud.com. NS
Answer
The response has no answer records.
Authority
ktcloud.com. 5279 SOA ns.kornet.net. domain.ns.kornet.net. 2026021301 43200 3600 604800 43200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0