halon04.reliablemail.org has no MX records.
Question and response
Question
dig halon04.reliablemail.org. MX
Answer
The response has no answer records.
Authority
reliablemail.org. 1800 SOA aron.ns.cloudflare.com. dns.cloudflare.com. 2396244391 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0