cebasp.edu.do has no MX records.
Question and response
Question
dig cebasp.edu.do. MX
Answer
cebasp.edu.do. 5 CNAME d2iy39oq5rlrcw.cloudfront.net.
Authority
cloudfront.net. 60 SOA ns-418.awsdns-52.com. hostmaster.cloudfront.net. 1377556270 16384 2048 1048576 60
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0