mx.developingsolutions.org has no MX records.
Question and response
Question
dig mx.developingsolutions.org. MX
Answer
The response has no answer records.
Authority
developingsolutions.org. 3600 SOA dns.developingsolutions.org. hostmaster.developingsolutions.org. 1516062193 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0