Apex domains cannot have CNAME records.
Question and response
Question
dig c3s2.iphmx.com. NS
Answer
c3s2.iphmx.com. 2 NS ns1-93.akam.net.
c3s2.iphmx.com. 2 NS use1.akam.net.
c3s2.iphmx.com. 2 NS ns1-73.akam.net.
c3s2.iphmx.com. 2 NS ns1-11.akam.net.
c3s2.iphmx.com. 2 NS asia3.akam.net.
c3s2.iphmx.com. 2 NS ns1-109.akam.net.
c3s2.iphmx.com. 2 NS ns1-117.akam.net.
c3s2.iphmx.com. 2 NS ns1-90.akam.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0