Apex domains cannot have CNAME records.
Question and response
Question
dig secmail.alpiq.services. NS
Answer
secmail.alpiq.services. 5 NS ns-1448.awsdns-53.org.
secmail.alpiq.services. 5 NS ns-688.awsdns-22.net.
secmail.alpiq.services. 5 NS ns-189.awsdns-23.com.
secmail.alpiq.services. 5 NS ns-1770.awsdns-29.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0