mailserver.dirfafinz.com.br has no NS records.
NS records for this zone are defined at dirfafinz.com.br.
NS records for this zone are defined at dirfafinz.com.br.
Question and response
Question
dig mailserver.dirfafinz.com.br. NS
Answer
The response has no answer records.
Authority
dirfafinz.com.br. 1800 SOA kim.ns.cloudflare.com. dns.cloudflare.com. 2393767287 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0