mx.ipcas.edu.do has no MX records.
Question and response
Question
dig mx.ipcas.edu.do. MX
Answer
The response has no answer records.
Authority
ipcas.edu.do. 86400 SOA ns2.infinityfree.com. support.ipcas.edu.do. 2006112402 28800 7200 604800 86400
Additional
. 0 OPT ; payload 1680, xrcode 0, version 0, flags 0