mail01.ipv4.datagroup.ua has no MX records.
Question and response
Question
dig mail01.ipv4.datagroup.ua. MX
Answer
The response has no answer records.
Authority
ipv4.datagroup.ua. 1800 SOA ns1.volia.net. hostmaster.volia.com. 2025111000 43200 3600 1814400 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0