minerd.net.do has no MX records.
Question and response
Question
dig minerd.net.do. MX
Answer
The response has no answer records.
Authority
minerd.net.do. 3600 SOA ns1-02.azure-dns.com. hostmaster.see.gob.do. 45 900 600 86400 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0