stroyunix.ispvds.com has no MX records.
Question and response
Question
dig stroyunix.ispvds.com. MX
Answer
The response has no answer records.
Authority
ispvds.com. 3600 SOA ns1.ispvds.com. tech.ispvds.com. 2017012570 10800 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0