relay.itsystems.ua has no MX records.
Question and response
Question
dig relay.itsystems.ua. MX
Answer
The response has no answer records.
Authority
itsystems.ua. 1800 SOA ns.itsinternet.net. hostmaster.itsinternet.net. 2026022701 43200 7200 1209600 7200
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0