tgrdev.smrussia.su has no MX records.
Question and response
Question
dig tgrdev.smrussia.su. MX
Answer
The response has no answer records.
Authority
smrussia.su. 600 SOA ns1.masterhost.ru. hostmaster.masterhost.ru. 1764417302 28800 7200 1209600 600
Additional
. 0 OPT ; payload 1680, xrcode 0, version 0, flags 0