pool.luganet.ru has no MX records.
Question and response
Question
dig pool.luganet.ru. MX
Answer
The response has no answer records.
Authority
luganet.ru. 10800 SOA luganet.ru. hostmaster.luganet.ru. 2020122201 3600 900 604800 10800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0