comail.siteexecutive.com has no MX records.
Question and response
Question
dig comail.siteexecutive.com. MX
Answer
The response has no answer records.
Authority
siteexecutive.com. 1800 SOA bethany.ns.cloudflare.com. dns.cloudflare.com. 2397121130 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0