mx00.mucix.net has no MX records.
Question and response
Question
dig mx00.mucix.net. MX
Answer
The response has no answer records.
Authority
mucix.net. 600 SOA dns0.noris.net. hostmaster.noris.net.mucix.net. 1771577726 86400 86400 2419200 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0