ns2.cometatelecom.com.br has no MX records.
Question and response
Question
dig ns2.cometatelecom.com.br. MX
Answer
The response has no answer records.
Authority
ns2.cometatelecom.com.br. 300 SOA ns2.cometatelecom.com.br. administrativo.cometatelecom.com.br. 2018021520 10800 3600 2419200 300
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0