ns.aironet.ru has no MX records.
Question and response
Question
dig ns.aironet.ru. MX
Answer
The response has no answer records.
Authority
aironet.ru. 7200 SOA ns.aironet.ru. wn.aironet.ru. 2023102643 7200 3600 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0