ns2.as44099.net has no MX records.
Question and response
Question
dig ns2.as44099.net. MX
Answer
The response has no answer records.
Authority
ns2.as44099.net. 600 SOA ns1.as44099.net. support.runiso.com. 2010070801 28800 7200 60480000 600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0