mx0.na4u.ru has no TXT records.
Question and response
Question
dig mx0.na4u.ru. TXT
Answer
The response has no answer records.
Authority
na4u.ru. 300 SOA ns1.netangels.ru. hostmaster.netangels.ru. 1772816770 3600 1800 1209600 3600
Additional
. 0 OPT ; payload 1280, xrcode 0, version 0, flags 0