fullsail.net.do has no MX records.
Question and response
Question
dig fullsail.net.do. MX
Answer
The response has no answer records.
Authority
fullsail.net.do. 300 SOA ns1.brandshelter.com. tech.brandshelter.com. 2012071005 10800 3600 604800 300
Additional
. 0 OPT ; payload 1400, xrcode 0, version 0, flags 0