mailserver.dirfsicredi.com.br has no NS records.
NS records for this zone are defined at dirfsicredi.com.br.
NS records for this zone are defined at dirfsicredi.com.br.
Question and response
Question
dig mailserver.dirfsicredi.com.br. NS
Answer
The response has no answer records.
Authority
dirfsicredi.com.br. 1800 SOA kim.ns.cloudflare.com. dns.cloudflare.com. 2397005403 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0