Gmail node common issues

Here are some common errors and issues with the Gmail node and steps to resolve or troubleshoot them.

Remove the n8n attribution from sent messages

If you're using the node to send a message or reply to a message, the node appends this statement to the end of the email:

To remove this attribution:

1. In the node's Options section, select Add option.
2. Select Append n8n attribution.
3. Turn the toggle off.

Refer to Send options and Reply options for more information.

Forbidden - perhaps check your credentials

This error displays next to certain dropdowns in the node, like the Label Names or IDs dropdown. The full text looks something like this:

There was a problem loading the parameter options from server: "Forbidden - perhaps check your credentials?"

The error most often displays when you're using a Google Service Account as the credential and the credential doesn't have Impersonate a User turned on.

Refer to Google Service Account: Finish your n8n credential for more information.

401 unauthorized error

The full text of the error looks like this:

401 - {"error":"unauthorized_client","error_description":"Client is unauthorized to retrieve access tokens using this method, or client not authorized for any of the scopes requested."}

This error occurs when there's an issue with the credential you're using and its scopes or permissions.

To resolve:

1. For OAuth2 credentials, make sure you've enabled the Gmail API in APIs & Services > Library. Refer to Google OAuth2 Single Service - Enable APIs for more information.
2. For Service Account credentials:
   1. Enable domain-wide delegation.
   2. Make sure you add the Gmail API as part of the domain-wide delegation configuration.

Bad request - please check your parameters

This error most often occurs if you enter a Message ID, Thread ID, or Label ID that doesn't exist.

Try a Get operation with the ID to confirm it exists.