mta2.spin.it has no CNAME records.
Question and response
Question
dig mta2.spin.it. NS
Answer
The response has no answer records.
Authority
spin.it. 7200 SOA up.spin.it. hostmaster.spin.it. 2025072300 86400 7200 2419200 7200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0