mx.matrixrelo.info has no MX records.
Question and response
Question
dig mx.matrixrelo.info. MX
Answer
The response has no answer records.
Authority
matrixrelo.info. 3600 SOA dns.matrixrelo.info. hostmaster.matrixrelo.info. 1522396137 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0