polygloter.learncognito.com has no MX records.
Question and response
Question
dig polygloter.learncognito.com. MX
Answer
The response has no answer records.
Authority
learncognito.com. 3600 SOA ns1.name.com. hostmaster.nsone.net. 1764501412 43200 7200 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0