What is an email defer error?

In simple terms, email defer is where the system starts rejecting outgoing email instead of queuing it once a user reaches the maximum allowed emails per hour.

Usually, this event is triggered when an account sends an email to addresses that fail or defer more than the set limit.

The "exceeded the max defers and failures per hour" message is an automated message that outgoing email is being held on the server until the number of emails that have failed or been deferred is below the email threshold.

The domain users are only able to send out the emails after 1 hour of the blocking period. The defer limit are various depend on the service subscribed.

An example of a Non-Delivery Report (NDR) error message.

Domain example.com has exceeded the max defers and failures per hour (25/25 (100%)) allowed. Message discarded.


  • Sending email from any of your domain email accounts fails
  • You receive a Non-Delivery Report (NDR) with the error shown above.

Possible Cause and Solution 

  • Your account has exceeded the allowed number of bounced messages per hour and as a result, your sending rights have been blocked.
  • The block is temporary and is removed on the hour.
  • This block is required to prevent your account from being permanently blocked by third party mail servers and spam blacklist.

1. The email address has been compromised to send out spam emails

If the user is experiencing the defer limit issue caused by compromised email accounts, we recommend changing the email password to stronger characters with at least 18 characters inclusive of upper and lower case letters, numbers, and symbols.

In addition, may also scan the computer with updated antivirus to remove any malware, adware, spyware, rootkits, trojans, etc.

If the issue still persists and if the user uses an email application such as Microsoft Outlook or Thunderbird, the user can temporarily disable the mail app to stop sending email from the email application. 

2. Bulk email sending (intentionally)

If the users experiencing the defer limit issue caused by intentionally sending out mass mailing/bulk emails for marketing purposes may consider subscribing to an Email Marketing Service which is more suited to the needs regarding bulk email delivery.

3. Mailbox full

If the users experiencing the defer limit issue caused by the recipient's full mailbox, you may contact the recipient to perform housekeeping to reduce email storage.

4. Email Forwarding

If a user experiences a defer limit issue caused by sending too many emails to the forwarding address, the user can log in to webmail and delete the associated forwarding address.

Next please be advised that configuring email forwarder to free email service provider such as Hotmail.com, Gmail.com is strictly not allowed in a shared hosting environment.


The block will be automatically removed on the hour. Please wait till an hour has passed to attempt to send the email again.


To prevent max defers and failures per hour error messages please check the following:

  • Ensure your account is not sending spam. Check your mail delivery reports. If you see a large number of delivery failures from one of your email addresses then we recommend immediately changing your mailbox password and virus scanning all your devices.
  • Check autoresponders and spam filters. This block can sometimes be triggered when you have an autoresponder set up to send an out-of-office reply to all emails you receive. This is because the autoresponder will reply to all emails including spam email addresses that do not exist. In these cases, the reply will fail which counts towards the delivery failure count per hour on your domain. To resolve this ensure your Spam Filters are enabled on your hosting account. This will ensure emails we flag as spam is not sent an autoresponse.
  • Check your mailing lists is up to date. If you are sending a mass marketing email, please check your mailing list is up to date by removing email addresses that no longer work. Sending to multiple invalid email addresses will trigger the block. The only way to resolve this is to clean your mail list and remove email addresses which result in bouncebacks.