mx1.mirohost.net has no CNAME records.
Question and response
Question
dig mx1.mirohost.net. NS
Answer
The response has no answer records.
Authority
mirohost.net. 52 SOA nsa2.srv53.net. support.dnshosting.org. 1771865247 1800 600 2419200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0