DO has no MX records.
Question and response
Question
dig DO. MX
Answer
The response has no answer records.
Authority
DO. 3600 SOA ns1.nic.DO. hostmaster.nic.DO. 2026031008 3600 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0