v3.sibdc.ru has no MX records.
Question and response
Question
dig v3.sibdc.ru. MX
Answer
The response has no answer records.
Authority
sibdc.ru. 43200 SOA ns1.snt.ru. dnsmaster.sinor.ru. 2026021600 86400 7200 1209600 345600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0