mail.goldvision.com has no CNAME records.
Question and response
Question
dig mail.goldvision.com. NS
Answer
The response has no answer records.
Authority
goldvision.com. 3588 SOA ns1.goldvision.com. support.goldvision.com. 1998103041 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0