mx20.ukraine.com.ua has no CNAME records.
Question and response
Question
dig mx20.ukraine.com.ua. NS
Answer
The response has no answer records.
Authority
ukraine.com.ua. 60 SOA ns1.ukraine.com.ua. hostmaster.adm.tools. 2026030560 43200 7200 604800 60
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0