mx04.communilink.net has no CNAME records.
Question and response
Question
dig mx04.communilink.net. NS
Answer
The response has no answer records.
Authority
communilink.net. 1800 SOA abby.ns.cloudflare.com. dns.cloudflare.com. 2395404742 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0