bl2.tolna.net has no MX records.
Question and response
Question
dig bl2.tolna.net. MX
Answer
The response has no answer records.
Authority
bl2.tolna.net. 86400 SOA ns.bl2.tolna.net. support.tolna.net. 2013121102 21600 7200 2419200 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0