cloudproxy10021.sucuri.net has no MX records.
Question and response
Question
dig cloudproxy10021.sucuri.net. MX
Answer
The response has no answer records.
Authority
sucuri.net. 7200 SOA 10.sucuridns.com. dcid.sucuri.net. 2026022001 14400 14400 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0