c0.nic.llc has no MX records.
Question and response
Question
dig c0.nic.llc. MX
Answer
The response has no answer records.
Authority
nic.llc. 300 SOA a0.nic.llc. alerts.afilias.info. 1772004791 86400 7200 3600000 172800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0