ns1.justhost.com has no MX records.
Question and response
Question
dig ns1.justhost.com. MX
Answer
The response has no answer records.
Authority
justhost.com. 1800 SOA cody.ns.cloudflare.com. dns.cloudflare.com. 2397675503 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0