Read SMTP Replies for Bounces

When you send an email to someone that bounces back, the server that bounced it typically includes an "SMTP Reply" that explains why the message bounced. Find that information in the header of the bounced message.

Understanding bounces

When MailChimp gets a bounced message, we try to read its SMTP reply and categorize the email as a "soft" or "hard" bounce for you. However, some email servers don't send bounces with properly formatted SMTP replies that use standard codes. In those cases, MailChimp has to make an educated guess as to how to categorize that bounced message. If you want to know specifically why a message bounced, or if you feel MailChimp categorized a bounce improperly, read its Bounce Reason to view the SMTP reply.

We also factor subscriber engagement activity into our bounce cleaning decisions.

Viewing bounce reasons

We log any bounces for a campaign in the campaign report. Bounce reasons are stored in the account for 30 days. Bounce reasons must be viewed individually for each bounce on a campaign, and it's not possible to export a full list of all the bounce reasons for a campaign. It's important that you check your bounces right away to ensure no valid emails bounced, that there were no syntax errors, and that you've manually cleaned your internal database if you need to.

To view the bounce reasons for a campaign follow these steps.

  1. Navigate to the Reports page.
  2. Click View report.
  3. Click the link for the number of Bounced emails for this campaign.

    row of data, including the number of bounces, which is a link to more information.

  4. On the Bounced page, click  Bounce Reason for each bounced address you want to investigate.
    A screenshot of the cursor clicking the bounce reason.
    You may have to scroll to the right to see the link if you have a lot of fields in your list. 

  5. After you click the Bounce Reason link, a report for the address opens in a separate browser tab detailing what caused the email to bounce.

subscriber activity, bounces

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