smtp0.mirasystem.net has no MX records.
Question and response
Question
dig smtp0.mail.miralogic.ru. MX
Answer
The response has no answer records.
Authority
miralogic.ru. 3600 SOA ns0.mirasystem.net. admins.mirasystem.net. 275 900 600 86400 3600
Additional
. 0 OPT ; payload 1680, xrcode 0, version 0, flags 0