136.47.202.in-addr.arpa has no MX records.
Question and response
Question
dig 136.47.202.in-addr.arpa. MX
Answer
The response has no answer records.
Authority
136.47.202.in-addr.arpa. 1800 SOA ns0.aics.ad.jp. hostmaster.aics.ad.jp. 3 10800 3600 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0