Deleting attachments leads to duplicate messages in Gmail

One of the most important Thunderbird features for me is the ability to delete attachments, but preserve the Email message, as it allows keeping the record of communication without also clogging the Email storage with unnecessary files.

However, I am using Gmail as my main Email account. When trying the deletion today:

• In Thunderbird, the Email hasn't changed and continues to be shown with the attachments deleted.
• In Gmail, both versions of the Email (with deleted dummy attachments and with the original attachments) are still visible.

Making matters more confusing, Gmail's threaded view shows the message without attachments before the original message.

Is there a known workaround?

Asking ChatGPT about it [link] points out that this is caused by how labels are mapped to Thunderbird, so from that perspective the behavior makes sense. This way I also found out, that the original message is still visibile under "All Mail". Even so, that makes the feature essentially a no-go. (

The mail thread as shown in Gmail (Print View). The text for the second message is hidden, because it is identical to the first message. In Thunderbird only the first message is visible now.