Debug Dynamic Emails
Gmail provides features to debug common issues with dynamic emails.
Enable the Fallback Debugging Banner in Gmail Web
Developers can enable a debugging banner to determine why their emails aren'trendering as AMP emails. The banner informs you that the AMP part of your emailisn't being rendered and provides a reason why. More information on each of thereasons can be found in the following section.
In order to enable the debugging banner for a specific email, you must whitelistthe sender's address in your developer settings and then refresh the page. RefertoTest your AMP emails inGmail for moreinformation.
Note: The banner doesn't appear if you have disabled dynamic email in thesettings panel. If you don't see the banner, ensure that you have enabled thesetting and refresh the page.Fallback Reasons
These are some of the common reasons that dynamic emails fail to render andinstead fall back to the to basic text or HTML.
| Fallback Reasons | |
|---|---|
ACCOUNT_TYPE | Dynamic emails aren't supported by your account type. Try using a new test Gmail account to view the email. |
AUTH_FAILED | The email failed one of theauthentication requirements. |
AUTO_FORWARDED | The email wasautomatically forwarded from a different account. For emails to render AMP content, make sure you open the email with the account it was sent to. |
BROWSER_ERROR | Something unexpected happened. Ensure you're using one of thesupported browsers and try again. |
DKIM_FAILED | The email failed Domain Keys Identified Mail (DKIM) authentication. See theauthentication requirements for more information. |
DKIM_NOT_MATCHING_FROM | The email failed Domain Keys Identified Mail (DKIM)alignment. |
DYNAMIC_EMAIL_DISABLED | Dynamic emails are disabled. Ensure thatDynamic email has been enabled in the Gmail settings panel. |
HIDING_IMAGES | TheAlways display external images setting is disabled. Re-enable this setting in the settings panel and refresh the page. |
INTERNAL_ERROR | Something unexpected happened in Gmail. |
INVALID_AMP | The AMP was invalid. See the AMP for Email spec for more information and follow thesteps to validate an AMP email. |
MALFORMED | The email contains more than onetext/x-amp-html part or no fallbacktext/html ortext/plain part. Seethe delivery requirements for more information. |
MESSAGE_CLIPPED | The email'stext/x-amp-html part is too long. See thedelivery requirements for more information. |
NOT_AVAILABLE_ON_PLATFORM | The sender has disabled dynamic content on this platform. If you are using the web client, try viewing the email on mobile. |
NOT_MAIN_WINDOW | The email was opened in a new window. Try opening this email in the main Gmail window. |
OFFLINE | The client is offline. Check your internet connection and try again. |
OLD_EMAIL | The email was sent over 30 days ago. |
PHISHY | The email was marked as phishing. Ensure that your email follows thesecurity requirements and email best practices. |
REFRESH_REQUIRED | The client needs to be refreshed. If you're using the web client and haven't enabled offline mode, refresh the page normally. If you have enabled offline mode, a hard refresh is required. If you're using a mobile app, try clearing app data and relaunching the app. |
SPAM | The email was marked as spam. Ensure that your email follows thesecurity requirements and email best practices. |
SPF_FAILED | The email failed Sender Policy Framework (SPF) authentication. See theauthentication requirements for more information. |
SUSPICIOUS | The email seems suspicious. Ensure that your email follows thesecurity requirements and email best practices. |
THREAD_TOO_LONG | The reply chain has become too long. Dynamic content is only rendered for the last 10 messages in a thread. |
TIMEOUT | The dynamic content took too long to load. Check your internet connection and try again. |
TLS_ENCRYPTION | The email wasn't TLS encrypted. Seethe TLS security requirement for more information and resend the email with TLS. |
TRANSLATED | Translation is enabled for the email. Disable automatic translation in Gmail and try again. |
WRONG_VERSION | Dynamic content isn't supported on your device. See the list ofsupported browsers for more information. |
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Last updated 2025-12-11 UTC.