rmail.whc.ca has no CNAME records.
Question and response
Question
dig rmail.whc.ca. NS
Answer
The response has no answer records.
Authority
whc.ca. 337 SOA coleman.ns.cloudflare.com. dns.cloudflare.com. 2397607117 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0