mail4.siaer.it has no NS records.
NS records for this zone are defined at siaer.it.
NS records for this zone are defined at siaer.it.
Question and response
Question
dig mail4.siaer.it. NS
Answer
The response has no answer records.
Authority
siaer.it. 1800 SOA aiden.ns.cloudflare.com. dns.cloudflare.com. 2397717804 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0