mail.cesena.net has no CNAME records.
Question and response
Question
dig mail.cesena.net. NS
Answer
The response has no answer records.
Authority
cesena.net. 1800 SOA edward.ns.cloudflare.com. dns.cloudflare.com. 2396941226 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0