smtp04.pr.gov.br has no MX records.
Question and response
Question
dig smtpfilter.pr.gov.br. MX
Answer
The response has no answer records.
Authority
pr.gov.br. 86400 SOA pr.gov.br. root.pr.gov.br. 2026022501 1800 300 3600000 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0