mx-outbound.graysmark.net has no MX records.
Question and response
Question
dig mx-outbound.graysmark.net. MX
Answer
The response has no answer records.
Authority
graysmark.net. 3600 SOA ns1.graysmark.net. hostmaster.graysmark.net. 2024102746 14400 1800 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0