Apex domains cannot have CNAME records.
Question and response
Question
dig epost.ca. NS
Answer
epost.ca. 5 NS ns-1413.awsdns-48.org.
epost.ca. 5 NS ns-1769.awsdns-29.co.uk.
epost.ca. 5 NS ns-467.awsdns-58.com.
epost.ca. 5 NS ns-952.awsdns-55.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0