mail.apple.ca has no CNAME records.
Question and response
Question
dig mail.apple.ca. NS
Answer
The response has no answer records.
Authority
apple.ca. 101 SOA ns-ext-prod.jackfruit.apple.com. dnscontact.apple.com. 63 7200 5400 3628800 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0