mx1.beget.pro has no CNAME records.
Question and response
Question
dig mx1.beget.pro. NS
Answer
The response has no answer records.
Authority
beget.pro. 116 SOA ns1.beget.com. hostmaster.beget.com. 1692616601 300 600 86400 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0