mail.icloudtech.dev has no CNAME records.
Question and response
Question
dig mail.icloudtech.dev. NS
Answer
The response has no answer records.
Authority
icloudtech.dev. 10459 SOA ns1.mastertel.ru. noc.mastertel.ru. 2022111000 28800 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0