dnsbox.net has no MX records.
Question and response
Question
dig dnsbox.net. MX
Answer
The response has no answer records.
Authority
dnsbox.net. 60 SOA ns.dnsbox.net. hostmaster.dnsbox.net. 2025041121 3600 1800 1209600 60
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0