Apex domains cannot have CNAME records.
Question and response
Question
dig pauspam.net. NS
Answer
pauspam.net. 5 NS ns-716.awsdns-25.net.
pauspam.net. 5 NS ns-1899.awsdns-45.co.uk.
pauspam.net. 5 NS ns-416.awsdns-52.com.
pauspam.net. 5 NS ns-1052.awsdns-03.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0