116.0.171.207.65.in-addr.arpa has no MX records.
Question and response
Question
dig 116.0.171.207.65.in-addr.arpa. MX
Answer
The response has no answer records.
Authority
0.171.207.65.in-addr.arpa. 3600 SOA ns1.silverpop.com. dnsadmin.silverpop.com. 2013012800 86400 7200 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0