mail.hiwaay.net has no MX records.
Question and response
Question
dig mail.hiwaay.net. MX
Answer
The response has no answer records.
Authority
hiwaay.net. 600 SOA ns1.hiwaay.net. hostmaster.hiwaay.net. 2019041843 86400 3600 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0