Fix "Exceeded Max Defers and Failures per Hour (55)" Email Error

Error Message: "Has exceeded the max defers and failures per hour (55 (100%)) allowed. Message discarded."

This error occurs when a mail server (usually configured with Exim or Postfix) detects that the number of deferred or failed email delivery attempts from your account exceeds the allowed limit set by the server administrator. The message is discarded to prevent potential abuse or spam-like behavior.

This error is common with bulk email sending, newsletters, or automated scripts that send to invalid email addresses.

What Causes This Error?

High Number of Failed Recipients:
- Emails are being sent to invalid or non-existent email addresses.
Spam-Like Behavior:
- Your email account or server may be flagged for sending too many messages, potentially marked as spam.
Improperly Configured Email Script or Software:
- A contact form, email marketing software, or other scripts may be trying to send emails to invalid addresses.
Compromised Email Account:
- Your email account may have been hacked and used to send spam.
Misconfigured Mail Server:
- The mail server may be rejecting outgoing emails due to incorrect DNS records or authentication settings.
Mail Server Limits:
- Hosting providers often set limits to prevent abuse (e.g., a maximum of 50 failed emails per hour).

How to Fix This Issue

Check the Email Addresses You're Sending To

Verify that the recipient email addresses are valid.
Remove invalid or outdated email addresses from your mailing list.

Tools to Verify Email Addresses:

Review Email Logs

Check the mail server logs to identify the cause of the failures or deferrals.

Exim Log Location:

For Exim (cPanel):
tail -f /var/log/exim_mainlog

Postfix Log Location:

For Postfix:
tail -f /var/log/mail.log

Look for errors like:

"Recipient address rejected."
"Relay access denied."

Check DNS Configuration

Ensure your DNS records for the email domain are configured correctly:

1. SPF Record:

Authorizes your server to send emails.
Example:
```
v=spf1 include:yourdomain.com ~all
```

2. DKIM Record:

Adds a digital signature to outgoing emails.

3. DMARC Record:

Protects against spoofing and phishing.

Use tools like MXToolbox to verify DNS settings.

Scan for Compromised Accounts

If an account is compromised, it may be sending spam.
Reset the password for the affected email account.
Enable two-factor authentication (2FA) for additional security.

Optimize Mailing Lists

Use a double opt-in process to collect email addresses.
Remove email addresses that bounce repeatedly.

Contact Your Hosting Provider

Request a temporary reset of the hourly sending limit.
Ask them to share logs or insights into why emails are being deferred or failing.

Increase Server Limits (if Allowed)

If you control the server (e.g., with WHM/cPanel):

Log in to WHM.
Navigate to:
Home > Service Configuration > Exim Configuration Manager
Adjust the following settings:
- Maximum percentage of failed or deferred messages a domain may send per hour:
  - Increase the percentage (e.g., from 50% to 70%).
- Maximum number of failed or deferred messages a domain may send per hour:
  - Increase the number if necessary.

Debug and Fix Sending Scripts

If a script (e.g., a contact form) is causing issues:
- Check for proper validation of email addresses.
- Ensure the script handles bouncebacks correctly.

Test Email Deliverability

Use tools like Mail Tester to check for spammy configurations or issues.

Prevent Future Issues

Regularly clean and verify email lists.
Monitor server logs to detect issues early.
Use a transactional email service like:
These services are more robust and can handle large volumes of email securely.

Error: "Has exceeded the max defers and failures per hour (55 (100%)) allowed. Message discarded."

What Causes This Error?

How to Fix This Issue

Check the Email Addresses You're Sending To

Tools to Verify Email Addresses:

Review Email Logs

Exim Log Location:

Postfix Log Location:

Check DNS Configuration

1. SPF Record:

2. DKIM Record:

3. DMARC Record:

Scan for Compromised Accounts

Optimize Mailing Lists

Contact Your Hosting Provider

Increase Server Limits (if Allowed)

Debug and Fix Sending Scripts

Test Email Deliverability

Prevent Future Issues

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Error: "Has exceeded the max defers and failures per hour (55 (100%)) allowed. Message discarded."

What Causes This Error?

How to Fix This Issue

Check the Email Addresses You're Sending To

Tools to Verify Email Addresses:

Review Email Logs

Exim Log Location:

Postfix Log Location:

Check DNS Configuration

1. SPF Record:

2. DKIM Record:

3. DMARC Record:

Scan for Compromised Accounts

Optimize Mailing Lists

Contact Your Hosting Provider

Increase Server Limits (if Allowed)

Debug and Fix Sending Scripts

Test Email Deliverability

Prevent Future Issues

Hosting

Cloud Solution

For You

VDS

Website Builders

Our services

Client Area

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