zaharov.aleksei.example.com has no MX records.
Question and response
Question
dig zaharov.aleksei.example.com. MX
Answer
The response has no answer records.
Authority
example.com. 1800 SOA elliott.ns.cloudflare.com. dns.cloudflare.com. 2396526872 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0