dns3.asdf456.com has no MX records.
Question and response
Question
dig dns3.asdf456.com. MX
Answer
The response has no answer records.
Authority
asdf456.com. 600 SOA dns2.asdf456.com. dns1.asdf456.com. 1771889729 600 600 600 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0