fbx.proxad.net has no MX records.
Question and response
Question
dig fbx.proxad.net. MX
Answer
The response has no answer records.
Authority
fbx.proxad.net. 600 SOA ns2.proxad.net. hostmaster.proxad.net. 2025050610 21600 3600 1209600 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0