org.mx has no MX records.
Question and response
Question
dig org.mx. MX
Answer
The response has no answer records.
Authority
org.mx. 1800 SOA m.mx-ns.mx. hostmaster.nic.mx. 1771783292 900 900 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0