mail.netbrasil.app.br has no MX records.
Question and response
Question
dig mail.netbrasil.app.br. MX
Answer
The response has no answer records.
Authority
netbrasil.app.br. 300 SOA ns1.netbrasil.app.br. hostmaster.netbrasil.app.br. 2026012384 14400 3600 2419200 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0