Apex domains cannot have CNAME records.
Question and response
Question
dig accelo.com. NS
Answer
accelo.com. 4 NS ns-284.awsdns-35.com.
accelo.com. 4 NS ns-2031.awsdns-61.co.uk.
accelo.com. 4 NS ns-1044.awsdns-02.org.
accelo.com. 4 NS ns-780.awsdns-33.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0