mail.3bears.com.ua has no MX records.
Question and response
Question
dig mail.3bears.com.ua. MX
Answer
The response has no answer records.
Authority
3bears.com.ua. 300 SOA ns1.tanhost.com. hostmaster.tanhost.com. 2024053101 1 1 3600000 300
Additional
. 0 OPT ; payload 1680, xrcode 0, version 0, flags 0