mx.cogecocommercial.ca has no CNAME records.
Question and response
Question
dig mx.cogecocommercial.ca. NS
Answer
The response has no answer records.
Authority
cogecocommercial.ca. 189 SOA ns4.cgocable.net. dnsadmin.cgocable.net. 2007012700 1800 900 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0