mint.ns37.net has no MX records.
Question and response
Question
dig mint.ns37.net. MX
Answer
The response has no answer records.
Authority
ns37.net. 300 SOA ns1.name.com. hostmaster.nsone.net. 1578427972 7200 3600 604800 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0