ns4.domwest.net has no MX records.
Question and response
Question
dig ns4.domwest.net. MX
Answer
The response has no answer records.
Authority
domwest.net. 1800 SOA ns1.domwest.net. hostmaster.domwest.net. 2015112600 28800 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0