In a hurry? Here's a quick workaround if you don't have time to troubleshoot: Deliver a message to an alternate email address
This article explains how to identify both the status and cause of a message that has failed to deliver to your mail server.
failed messages, the
Delivery logs will help identify the reason.
Hover over the message and click on the
The most important part of the delivery log will be highlighted in bright yellow to make it easy to find:
The three key pieces of information include:
sent - The message was successfully delivered to your mail server
deferred - The message is trying to deliver but experiencing a problem
bounced - The delivery attempt failed and will not be automatically tried again
expired - Despite repeated delivery attempts (for several days), the delivery was unsuccessful.
The response from your mail server can be difficult to understand. Following are some common error messages and an explanation of what they mean. If you don't see your error listed here, share the delivery log with your mail provider for assistance.
|No Such User Here
|The recipient email address does not exist on your mail server. Check the recipient address for typos.
|Mailbox is full
|The recipient email box (on your mail server) has too much mail and they need to remove some mail before your server will accept more mail on their behalf.
|Message size xxxx exceeds size limit xxxx of server
|Your mail server rejected the message because it was too large.
|Insufficient system resources
|Usually means your server is low on disk space or ram. See also:
Why is my mail deferring with an "Insufficient system resources" error?
|Please turn on SMTP Authentication in your mail client.
|Your mail server is not configured to accept mail for your domain. This most likely indicates that you need to follow these steps: Configuring cPanel with SpamHero
|Hop count exceeded - possible mail loop
|Messages are being redirected back to our servers after delivery (causing an infinite loop). If you are using Microsoft 365, see: The "Hop Count Exceeded", mail loop error analysis + solutions (Microsoft 365 / Office 365)
After resolving the issue that is causing mail to defer, our mail server will eventually deliver all messages queued for delivery. Or, you can re-attempt a delivery of all messages queued for delivery within 15 minutes by going to the Tools > Flush mail queue option example
Flushing the mail queue will only retry messages that are currently queued for delivery. For bounced and rejected messages, see: View or re-queue messages that failed to deliver