key3._domainkey.o-net.com.ua has no MX records.
Question and response
Question
dig key3.o-net.com.ua._domainkey.migadu.com. MX
Answer
The response has no answer records.
Authority
migadu.com. 3600 SOA ns0.migadu.com. hostmaster.migadu.com. 1772864227 1200 900 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0