204.174.185.in-addr.arpa has no MX records.
Question and response
Question
dig 204.174.185.in-addr.arpa. MX
Answer
The response has no answer records.
Authority
204.174.185.in-addr.arpa. 86400 SOA adns001.dc1.conova.com. domainadmin.conova.com. 2026011508 10800 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0