cek.GBlNET.net has no MX records.
Question and response
Question
dig cek.GBlNET.net. MX
Answer
The response has no answer records.
Authority
cek.GBlNET.net. 3600 SOA ns.gblnet.ru. vvv.gblnet.ru. 2023022301 10800 1200 1209600 259200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0