training.netstore.net has no MX records.
Question and response
Question
dig training.netstore.net. MX
Answer
The response has no answer records.
Authority
netstore.net. 86400 SOA auth1.dns.gxn.net. hostmaster.daisygroup.com. 2016050401 28800 7200 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0