mx201.unodata.com.br has no NS records.
NS records for this zone are defined at unodata.com.br.
NS records for this zone are defined at unodata.com.br.
Question and response
Question
dig mx201.unodata.com.br. NS
Answer
The response has no answer records.
Authority
unodata.com.br. 1800 SOA albert.ns.cloudflare.com. dns.cloudflare.com. 2398303949 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0