mail.ipl.edu.do has no MX records.
Question and response
Question
dig mail.ipl.edu.do. MX
Answer
The response has no answer records.
Authority
ipl.edu.do. 3600 SOA ipl.edu.do. hostmaster. 652 900 600 86400 3600
Additional
. 0 OPT ; payload 4000, xrcode 0, version 0, flags 0