_acme-challenge.arnsbogroup.com has no MX records.
Question and response
Question
dig arnsbogroup.com.kinstavalidation.app. MX
Answer
The response has no answer records.
Authority
kinstavalidation.app. 1800 SOA elliott.ns.cloudflare.com. dns.cloudflare.com. 2398358949 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0