131-161-0-21.avato.com.br has no MX records.
Question and response
Question
dig 131-161-0-21.avato.com.br. MX
Answer
The response has no answer records.
Authority
avato.com.br. 300 SOA nameserver1.avato.com.br. root.avato.com.br. 1771263686 3600 900 604800 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0