170.84.114.72.nippontec.net has no MX records.
Question and response
Question
dig 170.84.114.72.nippontec.net. MX
Answer
The response has no answer records.
Authority
nippontec.net. 3600 SOA nsa1.k8.com.br. dnsmasters.k8.com.br. 555 3600 300 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0