13.88.149.in-addr.arpa has no MX records.
Question and response
Question
dig 13.88.149.in-addr.arpa. MX
Answer
The response has no answer records.
Authority
13.88.149.in-addr.arpa. 86400 SOA ns1.jotelulu.com. nsmaster.jotelulu.com. 2024112800 28800 7200 604800 86400
Additional
. 0 OPT ; payload 1680, xrcode 0, version 0, flags 0