20.97.80.in-addr.arpa has no MX records.
Question and response
Question
dig 20.97.80.in-addr.arpa. MX
Answer
The response has no answer records.
Authority
20.97.80.in-addr.arpa. 0 SOA ns1.radiocomunicatii.ro. dragos.radiocom.ro. 2013100301 28800 3600 604800 0
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0