stronghold.fcomet.com has no MX records.
Question and response
Question
dig stronghold.fcomet.com. MX
Answer
The response has no answer records.
Authority
fcomet.com. 1800 SOA alex.ns.cloudflare.com. dns.cloudflare.com. 2398132049 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0