posta.nexis.it has no CNAME records.
Question and response
Question
dig posta.nexis.it. NS
Answer
The response has no answer records.
Authority
nexis.it. 300 SOA dns13.ovh.net. tech.ovh.net. 2025110400 86400 3600 3600000 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0