smtpfe.cnr.it has no CNAME records.
Question and response
Question
dig smtpfe.cnr.it. NS
Answer
The response has no answer records.
Authority
cnr.it. 1748 SOA dns.cnr.it. m\.astolfi.src.cnr.it. 2026030308 86400 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0