rbx5.piwbox.com has no MX records.
Question and response
Question
dig rbx5.piwbox.com. MX
Answer
The response has no answer records.
Authority
piwbox.com. 300 SOA dns111.ovh.net. tech.ovh.net. 2026021700 86400 3600 3600000 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0