highspeed2.net.br has no MX records.
Question and response
Question
dig highspeed2.net.br. MX
Answer
The response has no answer records.
Authority
highspeed2.net.br. 3600 SOA ns1.highspeed2.net.br. suporte.aprimorar.net.br.highspeed2.net.br. 1633194118 3600 600 1209600 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0