mx1.brdrive.net has no CNAME records.
Question and response
Question
dig mx1.brdrive.net. NS
Answer
The response has no answer records.
Authority
brdrive.net. 596 SOA ns4.brdrive.net. suporte.brdrive.net. 2026021600 3600 900 604800 900
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0