mail-vm.SAMARALAN.RU has no CNAME records.
Question and response
Question
dig mail-vm.SAMARALAN.RU. NS
Answer
The response has no answer records.
Authority
samaralan.ru. 9455 SOA ns1.samaralan.ru. dav.ns1.samaralan.ru. 2025111101 3600 60 200000 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0