smx1.hoster.by has no MX records.
Question and response
Question
dig smx1.hoster.by. MX
Answer
The response has no answer records.
Authority
hoster.by. 600 SOA dns1.hoster.by. support.hoster.by. 2026022500 900 600 86400 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0