mail.printnet.com.ua has no MX records.
Question and response
Question
dig mail.printnet.com.ua. MX
Answer
The response has no answer records.
Authority
printnet.com.ua. 3600 SOA nsa3.srv53.net. support.dnshosting.org. 1735218007 1800 600 2419200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0