ntp01.ivatel.com.br has no MX records.
Question and response
Question
dig ntp01.ivatel.com.br. MX
Answer
The response has no answer records.
Authority
ivatel.com.br. 38400 SOA ns1.ivatel.com.br. suporte.ivatel.com.br. 1476721570 10800 3600 604800 38400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0