Apex domains cannot have CNAME records.
Question and response
Question
dig e.d-53.net. NS
Answer
e.d-53.net. 1 NS ns.iij-dns.biz.
e.d-53.net. 1 NS ns.iij-dns.jp.
e.d-53.net. 1 NS ns.iij-dns.net.
Authority
The response has no authority records.
Additional
ns.iij-dns.net. 1 A 210.138.20.112
ns.iij-dns.net. 1 AAAA 2001:240:bb81:0:0:0:29:112
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0