ASNIC.US has no MX records.
Question and response
Question
dig ASNIC.US. MX
Answer
The response has no answer records.
Authority
ASNIC.US. 600 SOA ns33.domaincontrol.com. dns.jomax.net. 2025112805 28800 7200 604800 600
Additional
. 0 OPT ; payload 1280, xrcode 0, version 0, flags 0