ns2.outdns.net has no MX records.
Question and response
Question
dig ns2.outdns.net. MX
Answer
The response has no answer records.
Authority
outdns.net. 3600 SOA ns1.outdns.net. reportes.outper.net. 2014082701 3600 3600 777600 3600
Additional
. 0 OPT ; payload 1680, xrcode 0, version 0, flags 0