ALERT: Some images may not load properly within the Knowledge Base Article. If you see a broken image, please right-click and select 'Open image in a new tab'. We apologize for this inconvenience.
451 4.1.8 Domain of sender address does not resolve
Article ID: 214073
Messages are queued in the Delivery queue with the status "451 4.1.8 Domain of sender address does not resolve"
Example in Message Audit Log:
The destination mail server is unable to resolve the sender domain in DNS
Ensure that the sender domain has either an MX record or an A record in the public DNS.