Apex domains cannot have CNAME records.
Question and response
Question
dig enfohost.fi. NS
Answer
enfohost.fi. 3 NS ns1.enfo.fi.
enfohost.fi. 3 NS ns2.enfo.fi.
enfohost.fi. 3 NS ns4.enfo.fi.
enfohost.fi. 3 NS ns3.enfo.fi.
enfohost.fi. 3 NS ns5.enfogroup.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0