How troubleshoot undelivered Campaign messages

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There are many reasons a Campaign message may be marked as undelivered. If you notice a high number of undelivered Campaign emails, here are the steps you can take to check for possible reasons.

  1. Locate the Campaign in the Campaign Overview page.
  2. Click the ellipsis on the right of the Campaign and select 'Export analytics (CSV)'.
  3. In the CSV, there is a column header for "reason". If the server returned a message when the email was undelivered, the error explanation will be listed here.


Example of a possible error: 

550 5.7.26 Unauthenticated email is not accepted due to domain's DMARC policy. Please contact the administrator  if this was a legitimate mail. Please visit to learn about the DMARC initiative. l11-20020a9d550b000000b00638977af2aesi2038928oth.95 - gsmtp

This error indicates the domain address sending the email has not been verified. The address would need to be verified before emails can be sent from it. 

Read more on custom domains and branding tracking here.