mx4.timeweb.ru has no MX records.
Question and response
Question
dig mx4.timeweb.ru. MX
Answer
The response has no answer records.
Authority
mx4.timeweb.ru. 600 SOA ns1.timeweb.ru. dns.timeweb.ru. 496 28800 7200 604800 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0