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How to fix hard bounces

What does a Hard Bounce mean?

If you see a Hard Bounce for a recipient in your activity, that means the message sent to them bounced due to the address being deemed permanently invalid. If you expand the bounce information using the More Details button, you can get a bit more insight into why the address was deemed bad.

For example:

Final-Recipient: rfc822;someone@misspelleddomain.co
Action: failed
Status: <strong>5.1.2 (bad destination system: no such domain)
</strong>X-PowerMTA-BounceCategory: <strong>bad-domain</strong>

More Details screen for a hard bounce

Using these details you can get a clearer picture of what is wrong with the address. In this particular example, the domain was bad and does not exist or has no MX record set up for it.

How do I fix it?

To resolve the bounce, you would first want to determine if the address is actually valid or if it was bad due to a simple typo. You can review the address for accuracy and if it looks correct then you’ll want to:

  1. Search and view the Hard Bounced message within your Message Stream’s Activity area.
  2. Select the More Details button to view the bounce error. It’ll look something like:
    Final-Recipient: rfc822;someone@misspelleddomain.co
    Action: failed<br>Status: 5.1.1 (bad destination mailbox address)
    Diagnostic-Code: smtp;550 5.1.1 <someone@misspelleddomain.co> Recipient not found.
    X-PowerMTA-BounceCategory: bad-mailbox<br>
    	
  3. Copy and share the bounce error details with the recipient in a channel outside of Postmark.
  4. The recipient may just need to add your FROM domain to their contact list, or work with their mail / IT admins to whitelist Postmark’s sending IPs.
  5. Once the issue is resolved on the receiving end, you can then reactivate the recipient’s email address.

Once reactivated, you are all set to send to that recipient again and if they resolved the cause of the bounce, you will then get a successful Delivered event in Postmark instead of another bounce.

Testing Hard Bounces

Want to integrate with the Postmark Bounces API or Bounces webhook to get notified of Hard Bounces? Postmark offers a black hole domain that allows you to test all possible bounce responses and each of these will trigger the bounce webhook. Emails sent to that domain do not affect your sending reputation.

Last updated June 30th, 2021

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