129.84.62.in-addr.arpa has no MX records.
Question and response
Question
dig 129.84.62.in-addr.arpa. MX
Answer
The response has no answer records.
Authority
129.84.62.in-addr.arpa. 86400 SOA ns.sbone.cz. hostmaster.cz.net. 2021111565 28800 7200 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0