mx1.pgmail.com.br has no NS records.
NS records for this zone are defined at pgmail.com.br.
NS records for this zone are defined at pgmail.com.br.
Question and response
Question
dig mx1.pgmail.com.br. NS
Answer
The response has no answer records.
Authority
pgmail.com.br. 1800 SOA kaiser.ns.cloudflare.com. dns.cloudflare.com. 2396043802 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0