Apex domains cannot have CNAME records.
Question and response
Question
dig netmxserver.net. NS
Answer
netmxserver.net. 4 NS ns16.domaincontrol.com.
netmxserver.net. 4 NS ns15.domaincontrol.com.
Authority
The response has no authority records.
Additional
ns15.domaincontrol.com. 3 A 97.74.107.8
ns16.domaincontrol.com. 3 A 173.201.75.8
ns15.domaincontrol.com. 3 AAAA 2603:5:21b0:0:0:0:0:8
ns16.domaincontrol.com. 3 AAAA 2603:5:22b0:0:0:0:0:8
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0