Apex domains cannot have CNAME records.
Question and response
Question
dig relai-smtp.net. NS
Answer
relai-smtp.net. 4 NS ns1.domwest.net.
relai-smtp.net. 4 NS ns4.domwest.net.
relai-smtp.net. 4 NS ns3.domwest.net.
relai-smtp.net. 4 NS ns2.domwest.net.
Authority
The response has no authority records.
Additional
ns1.domwest.net. 4 A 147.135.181.139
ns2.domwest.net. 4 A 212.83.139.143
ns3.domwest.net. 4 A 188.165.51.166
ns4.domwest.net. 4 A 178.32.244.176
ns1.domwest.net. 4 AAAA 2001:41d0:d:289b:0:0:79:104
ns2.domwest.net. 4 AAAA 2001:bc8:3956:280:104:0:0:0
ns3.domwest.net. 4 AAAA 2001:41d0:a:7987:2:0:0:104
ns4.domwest.net. 4 AAAA 2001:41d0:1008:4c6:0:76:2:104
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0