96.12.190.in-addr.arpa has no MX records.
Question and response
Question
dig 96.12.190.in-addr.arpa. MX
Answer
The response has no answer records.
Authority
96.12.190.in-addr.arpa. 10800 SOA ns1.cps.com.ar. hostmaster.cps.com.ar. 2010100864 3600 900 1209600 43200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0