Email failure reasons

This article explains the different reasons why an email might fail to send on Mailmeteor. When an email fails to send, it’s marked as “failed” in the dashboard. You’ll also see a failure reason code, which you can reference here to understand the underlying issue.

  • user_blocked: Your Mailmeteor account has been blocked.
  • user_quota_exhausted: You have reached your sending quota limit. Upgrade your plan to increase your quota.
  • reached_limit: You have reached a limit for sending email (learn more).
  • too_many_retries: Mailmeteor has retried sending the email too many times. We’ll retry up to 5 times before marking an email as failed.

Campaign issues

  • campaign_canceled: The campaign was canceled before this email could be sent.
  • campaign_archived: The campaign was archived before this email could be sent.
  • campaign_paused: The campaign was paused before this email could be sent.
  • campaign_resumed_after_schedule: The campaign was paused then resumed, but this email was scheduled prior to the resume date.
  • unsubscribed_recipients: Some recipients have unsubscribed from your emails.
  • blocked_recipients: Some recipients have blocked your emails.
  • missing_recipients: No recipients specified in the email.
  • too_many_recipients: The email has too many recipients. Reduce the number of recipients and try again.

Content-related issues

  • too_many_recipients: You have exceeded the maximum number of recipients allowed per campaign.
  • too_many_retries: The system attempted to send the email too many times without success. Contact support if you see this error frequently.
  • invalid_to_header: The “To” header is invalid.
  • invalid_cc_header: The “CC” header is invalid.
  • invalid_bcc_header: The “BCC” header is invalid.
  • invalid_reply_to_header: The “Reply-To” header is invalid.
  • invalid_in_reply_to: The “In-Reply-To” header is invalid.
  • invalid_attachments: The email included attachments that are corrupt or invalid.
  • attachment_empty: You tried to attach an empty file.
  • attachment_too_large: The attachment exceeds the maximum allowed size.
  • attachment_not_public: The attachment is not publicly accessible.
  • attachment_not_found: The specified attachment could not be found.
  • attachments_fetch_failed: There was an error downloading the attachments from the provided URL.
  • attachments_max_files_exceeded: You tried to attach more files than the allowed limit.
  • attachments_max_size_exceeded: The total size of the attachments exceeds the allowed limit.

OAuth issues

These failure reasons are related to account authorization with your email service provider (e.g. Gmail or Outlook). They typically indicate an issue with how your account is connected. You may need to reconnect your account in Mailmeteor to fix the issue.

Common reasons for these errors include:

  • oauth_scopes_required: You have provided insufficient permissions/scopes.
  • oauth_insufficient_permission: The OAuth token has insufficient permissions.
  • oauth_unauthorized_client: The OAuth client is unauthorized.
  • oauth_invalid_grant: The OAuth grant is invalid.
  • oauth_invalid_request: The OAuth request is invalid.
  • oauth_invalid_client: The OAuth client is invalid.
  • oauth_unsupported_grant_type: The OAuth grant type is unsupported.
  • oauth_invalid_scope: The OAuth scope is invalid.
  • oauth_invalid_credentials: The OAuth credentials are invalid.
  • oauth_admin_policy_enforced: An admin policy is enforcing restrictions on the OAuth client.
  • oauth_missing_token: The OAuth token is missing.
  • oauth_unauthorized_to_refresh_token: The client is unauthorized to refresh the OAuth token.

Gmail API failures

These failure reasons are specific to sending emails via Gmail. They typically indicate a problem with the Gmail service or your integration with Gmail. If you encounter any of these errors, it may be necessary to check your Gmail account settings, ensure that Gmail API access is properly configured, or wait for any temporary issues with Gmail to be resolved. Common reasons for these errors include:

  • missing_in_gmail: The email could not be found in Gmail.
  • gmail_api_rate_limit_exceeded: The Gmail API rate limit has been exceeded. Wait and try again later.
  • gmail_api_captcha: A CAPTCHA is required by Gmail API.
  • gmail_api_internal_error: An internal error occurred in the Gmail API.
  • gmail_api_not_enabled: The Gmail API is not enabled for your account.

For further assistance or if you have any questions, please contact our support team.

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