Apex domains cannot have CNAME records.
Question and response
Question
dig estraspa.it. NS
Answer
estraspa.it. 5 NS dns01.estracom.it.
estraspa.it. 5 NS dns02.estracom.it.
Authority
The response has no authority records.
Additional
dns01.estracom.it. 5 A 83.149.128.94
dns02.estracom.it. 5 A 83.149.128.95
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0