test-smtp2.miran.tech has no CNAME records.
Question and response
Question
dig test-smtp2.miran.tech. NS
Answer
The response has no answer records.
Authority
miran.tech. 3600 SOA ns.miran.ru. adm.miran.ru. 2020081694 10800 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0