dnsalias.net has no MX records.
Question and response
Question
dig dnsalias.net. MX
Answer
The response has no answer records.
Authority
dnsalias.net. 600 SOA ns1.dyndns.org. hostmaster.dyndns.org. 2220095950 600 300 604800 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0