ns5.g-cloud.by has no MX records.
Question and response
Question
dig ns5.g-cloud.by. MX
Answer
The response has no answer records.
Authority
g-cloud.by. 43200 SOA ns1.g-cloud.by. tech.g-cloud.by. 2018117141 10800 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0