relay3.msk-ix.ru has no MX records.
Question and response
Question
dig relay3.msk-ix.ru. MX
Answer
The response has no answer records.
Authority
msk-ix.ru. 1800 SOA ns.msk-ix.ru. noc-dns.msk-ix.ru. 650127953 86400 3600 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0