ns2.ajato.com.br has no MX records.
Question and response
Question
dig ns2.ajato.com.br. MX
Answer
The response has no answer records.
Authority
ajato.com.br. 7200 SOA aquarius.vivo.com.br. root.ajato.com.br. 2106077921 10200 3600 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0