mail3.cvc.com.br has no MX records.
Question and response
Question
dig mail3.cvc.com.br. MX
Answer
The response has no answer records.
Authority
cvc.com.br. 300 SOA ns1.p201.dns.oraclecloud.net. hostmaster.cvc.com.br. 150 3600 600 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0