ns.cable.tolna.net has no MX records.
Question and response
Question
dig ns.cable.tolna.net. MX
Answer
The response has no answer records.
Authority
cable.tolna.net. 86400 SOA ns.cable.tolna.net. support.tolna.net. 2013121103 21600 7200 2419200 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0