smtp.irideos.it has no CNAME records.
Question and response
Question
dig smtp.irideos.it. NS
Answer
The response has no answer records.
Authority
irideos.it. 9250 SOA ns.kpnqwest.it. hostmaster.kpnqwest.it. 2026030523 86400 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0