Apex domains cannot have CNAME records.
Question and response
Question
dig cmcpaging.com. NS
Answer
cmcpaging.com. 5 NS ns-719.awsdns-25.net.
cmcpaging.com. 5 NS ns-1530.awsdns-63.org.
cmcpaging.com. 5 NS ns-1511.awsdns-60.org.
cmcpaging.com. 5 NS ns-976.awsdns-58.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0