mail.register.it has no CNAME records.
Question and response
Question
dig mail.register.it. NS
Answer
The response has no answer records.
Authority
register.it. 6637 SOA ns1.register.it. hostmaster.register.it. 2026022401 10800 3600 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0