_netblock-ipv6.netangels.ru has no MX records.
Question and response
Question
dig _netblock-ipv6.netangels.ru. MX
Answer
The response has no answer records.
Authority
netangels.ru. 300 SOA ns1.netangels.ru. hostmaster.netangels.ru. 1772144635 3600 1800 1209600 3600
Additional
. 0 OPT ; payload 1280, xrcode 0, version 0, flags 0