mailtest.net.vodafone.it has no CNAME records.
Question and response
Question
dig mailtest.net.vodafone.it. NS
Answer
The response has no answer records.
Authority
net.vodafone.it. 900 SOA nsmob1.net.vodafone.it. hostmaster.vodafone.it. 2004105963 10800 3600 2592000 900
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0