spf.webcerta.net.br has no MX records.
Question and response
Question
dig spf.webcerta.net.br. MX
Answer
The response has no answer records.
Authority
webcerta.net.br. 86400 SOA ns1.w3connect.com.br. logs.deieno.com.br. 2026012601 3600 1800 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0