mailrelay.it.ntta.com has no NS records.
NS records for this zone are defined at it.ntta.com.
NS records for this zone are defined at it.ntta.com.
Question and response
Question
dig mailrelay.it.ntta.com. NS
Answer
The response has no answer records.
Authority
it.ntta.com. 300 SOA ns1-07.azure-dns.com. ntta.it.systems.storage.global.ntt. 2021081501 3600 600 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0