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Emails Failing

Diagnosing the Issue​

If emails are failing and the site uses Fluent SMTP:

  1. Navigate to Fluent SMTP > Email Logs in the WordPress admin
  2. Check the log entries for failed emails
  3. Note the error code and message for troubleshooting

Common Causes​

Blocked Email Address in Postmark​

If only a single user is unable to receive emails, their email address may be blocked in Postmark's suppression list.

To check and resolve:

  1. Log into the Postmark dashboard
  2. Navigate to Suppressions under the relevant server
  3. Search for the affected email address
  4. If found, remove it from the suppression list (after confirming the issue that caused the block is resolved)

Other Common Issues​

  • Invalid API credentials - Verify the Postmark API key in Fluent SMTP settings
  • Sender signature not verified - Ensure the sending domain/email is verified in Postmark
  • Rate limiting - Check if sending limits have been exceeded

Client Communication​

What this means: We use a professional email service called Postmark to deliver emails reliably, rather than relying on Wordpress's built in email sending. Sometimes an email address gets blocked if previous emails bounced or were marked as spam. This is beneficial behaviour as it keeps the reputation clean and ensures errors do not cause emails to bounce for valid users due to spam filters etc.

Example message to client:

Hi [Name],

We've looked into the email issue and found that [recipient's email] was blocked by our email delivery service due to [previous bounces/spam complaints].

We've removed the block and emails should now deliver normally. If the issue continues, please let us know.