mat0.cryptinfo.site has no MX records.
Question and response
Question
dig mat0.cryptinfo.site. MX
Answer
The response has no answer records.
Authority
site. 900 SOA ns0.centralnic.net. hostmaster.centralnic.net. 423337 900 1800 6048000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0