adns1.south.rt.RU has no MX records.
Question and response
Question
dig adns1.south.rt.RU. MX
Answer
The response has no answer records.
Authority
south.rt.ru. 3600 SOA ns1.kes.ru. root.ip.rostelecom.ru. 2026030500 86400 3600 604800 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0