dat2.redcom.ru has no MX records.
Question and response
Question
dig dat2.redcom.ru. MX
Answer
The response has no answer records.
Authority
redcom.ru. 86400 SOA ns.redcom.ru. hostmaster.redcom.ru. 2026021801 28800 3600 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0