mx.planethoster.net has no MX records.
Question and response
Question
dig mx.planethoster.net. MX
Answer
The response has no answer records.
Authority
planethoster.net. 14400 SOA nsa.n0c.com. hostmaster.planethoster.net. 2025121904 3600 1800 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0