Troubleshoot reply by email

If your Discourse does not have incoming email set up, see these topics:

:information_source: If you already have basic reply via email set up (which is common on hosting plans), and you want to add the ability to start a new topic via email, see this topic.

Logging and Errors

All incoming emails are logged and are visible in your admin panel at /admin/email/received. You can filter the list using the From, To and Subject field of the emails.

The rejected list (/admin/email/rejected) is much more useful when it comes to understand things. You can filter the list using the From, To and Subject field of the emails as well as the Error message.

At any time, you can click the Error message and a modal will show up with more details. If it’s a known error, you will find a small description explaining why that email was rejected. Then you will find all the headers of the email, the subject and the first 100 words of the raw version of the body. Finally, you will find the rejection email that was sent back to the user.

Among all the known errors, two are more common:

  • reply_user_not_matching_error: a reply came in from a different email address the notification was sent to.

This happens when someone uses more than one email addresses (using email aliases for example) but only reply using one email address. Let’s say that the user registered an account with foo+discourse@bar.com.

  • auto_generated_email_error: happens when at least one of the following criteria is matched
    • the ‘precedence’ header is set to: list, junk, bulk or auto_reply
    • the email is from mailer-daemon, postmaster or noreply
    • any of the headers contain: auto-submitted, auto-replied, auto-reply or auto-generated (non exhaustive list).

Since there is no standard to identify automatic emails we have to use regular expressions to match the most commonly used words and headers. These errors are usually safe to ignore but if you find a genuine email that was mis-classified, then be sure to report it here.

Here are the other known errors you might encounter:

  • empty_email_error: the raw mail we received was blank.
  • user_not_found_error: when staged users is disabled and the sender is not an existing user.
  • no_body_detected_error: we couldn’t extract a body and there was no attachments.
  • inactive_user_error: the sender is not active.
  • silenced_user_error: the sender has been silenced.
  • bad_destination_address: none of the email addresses in the To, Cc and Bcc fields matched a configured incoming email address.
  • strangers_not_allowed_error: a user tried to create a new topic in a category they’re not a member of.
  • insufficient_trust_level_error: a user tried to create a new topic in a category they don’t have the required trust level for.
  • topic_not_found_error: a reply came in but the related topic has been deleted.
  • topic_closed_error: a reply came in but the related topic has been closed.

Related Topics


Last Reviewed by @SaraDev on 2022-06-06T19:00:00Z

Last edited by @JammyDodger 2024-05-28T18:44:17Z

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