ns0.extrim.ru has no MX records.
Question and response
Question
dig ns0.extrim.ru. MX
Answer
The response has no answer records.
Authority
extrim.ru. 86400 SOA ns0.mirasystem.net. admins.mirasystem.net. 2007096215 3600 1800 604800 86400
Additional
. 0 OPT ; payload 1680, xrcode 0, version 0, flags 0