mail.managedns.ca has no CNAME records.
Question and response
Question
dig mail.managedns.ca. NS
Answer
The response has no answer records.
Authority
managedns.ca. 2312 SOA ns3.managedns.ca. noc.canhost.ca. 2014081108 3600 3600 604800 10800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0