relay2.yaroslavl.ru has no MX records.
Question and response
Question
dig relay2.yaroslavl.ru. MX
Answer
The response has no answer records.
Authority
yaroslavl.ru. 300 SOA ns.innet.yaroslavl.su. hostmaster.innet.yaroslavl.su. 2147488568 21600 10800 604800 10800
Additional
. 0 OPT [{Extended_DNS_Error: PROHIBITED}] ; payload 1232, xrcode 0, version 0, flags 0