mail.yus.ru has no MX records.
Question and response
Question
dig mail.yus.ru. MX
Answer
The response has no answer records.
Authority
yus.ru. 3600 SOA isp4.wm.ru. dnsmaster.wm.ru. 2019022884 3600 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0