dns.site5.com has no MX records.
Question and response
Question
dig dns.site5.com. MX
Answer
The response has no answer records.
Authority
site5.com. 1800 SOA cody.ns.cloudflare.com. dns.cloudflare.com. 2396368063 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0