msk.ru has no MX records.
Question and response
Question
dig msk.ru. MX
Answer
The response has no answer records.
Authority
msk.ru. 3600 SOA ns3-geo.nic.ru. hostmaster.nic.ru. 387747 7200 900 2592000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0