204.246.77.in-addr.arpa has no MX records.
Question and response
Question
dig 204.246.77.in-addr.arpa. MX
Answer
The response has no answer records.
Authority
204.246.77.in-addr.arpa. 3600 SOA ns1.suomicom.fi. domains.suomicom.fi. 1764170835 28800 3600 864000 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0