Apex domains cannot have CNAME records.
Question and response
Question
dig emailme.com. NS
Answer
emailme.com. 5 NS ns5.centralnic-dns.com.
emailme.com. 5 NS ns4.centralnic-dns.com.
emailme.com. 5 NS ns3.centralnic-dns.com.
emailme.com. 5 NS ns0.centralnic-dns.com.
emailme.com. 5 NS ns2.centralnic-dns.com.
emailme.com. 5 NS ns1.centralnic-dns.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0