mail.bearstech.com has no CNAME records.
Question and response
Question
dig mail.bearstech.com. NS
Answer
The response has no answer records.
Authority
bearstech.com. 298 SOA ns1.bearstech.net. admin.bearstech.com. 2026022301 1800 1800 604800 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0