mx10.DHUB.RU has no TXT records.
Question and response
Question
dig mx10.DHUB.RU. TXT
Answer
The response has no answer records.
Authority
DHUB.RU. 3600 SOA ns3.DHUB.RU. administrator.DHUB.RU. 357 900 600 86400 3600
Additional
. 0 OPT ; payload 4000, xrcode 0, version 0, flags 0