cgate.SINTEC.RU has no MX records.
Question and response
Question
dig cgate.SINTEC.RU. MX
Answer
The response has no answer records.
Authority
SINTEC.RU. 600 SOA ext01-1.SINTEC.RU. root.SINTEC.RU. 2026010702 3600 600 864000 600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0