If you do a web search for "how to delete attachments from gmail" you will find lots of sites that focus on removing attachments but keeping the messages, but all of them point to the fact that you stated: they stick with the message. Maybe someone here will have suggestions, but it doesn't look promising.

See https://kb.mozillazine.org/Saving_and_detaching_attachments

Hi Simon,

When you detach attachments from emails in Thunderbird, it only affects the local copy of the email stored in Thunderbird. The original email in Gmail remains unchanged because Gmail does not have a built-in "detach" function like Thunderbird.

1. 1. 1. What Happens When You Detach an Attachment in Thunderbird?

- The attachment is removed from the local copy in Thunderbird and saved separately as a file. - However, if you're using IMAP (which syncs emails with the Gmail server), Thunderbird does **not** modify the email on Gmail’s servers. Gmail retains the original email with the attachment.

1. 1. 1. How to Truly Remove Attachments from Gmail?

Since Gmail does not have a "detach" function, you can: 1. Manually delete the attachment – Forward the email to yourself without the attachment and delete the original. 2. Use Google Takeout – Download emails for offline storage, then delete large emails from Gmail. 3. Third-party tools – Some third-party Gmail add-ons can help remove attachments while keeping the email content.

If you're looking to free up Gmail storage, you might want to filter and delete emails with large attachments using Gmail’s search (`has:attachment larger:10MB`).

Hope this helps! Let me know if you need further clarification.

Best,