tolyatti.admin.sardinasystems.com has no MX records.
Question and response
Question
dig tolyatti.admin.sardinasystems.com. MX
Answer
The response has no answer records.
Authority
admin.sardinasystems.com. 60 SOA a.ns.admin.sardinasystems.com. hostmaster.admin.sardinasystems.com. 1772273068 300 60 604800 60
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0