When sending to an email address results in a hard bounce, Resend places this address on the Suppression List. Emails placed on the list cannot be sent to until they are removed.
We place emails on the Suppression List to protect domain reputation, both yours and ours. Sending an email to a known hard bounce recipient can damage domain reputation and affect email deliverability.

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Reasons emails are placed on the Suppression List

Here are some possible reasons an email address is placed on the Suppression List:
  • The recipient’s email address contains a typo.
  • The recipient’s email address doesn’t exist.
  • The recipient’s email server has permanently blocked delivery.

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View email bounce details

You can view the reason an email bounced on the Emails page. Open the Emails page and search for the recipient’s email address in question. A human-readable summary of the reason for the bounce displays. For more technical details and suggested next steps, click the See details button. Email Bounced button

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Removing an email address from the Suppression List

You may be able to send a message to the same recipient in the future if the issue that caused the message to bounce is resolved and the email address is removed from the Suppression List.
Remember, if you do not address the issue that caused the email to bounce, the email address will return to the Suppression List the next time you attempt to send to it.
To remove your recipient from the Suppression List, click on the email in the emails dashboard, and click Remove from suppression list. Email Bounced button