Hi Fred I am not expert in the interaction between Thunderbird and Gmail but there are some basic concepts with Gmail that complicate the way it matches up with Thunderbird Inbox and folders. Gmail has inbox and other folders, but it also creates a 'view' of all the email in one place - All Mail. That includes everything from all folders - so even when you "move" something to a specific folder, it also appears in All Mail. In Thunderbird, you probably want to subscribe only to Inbox (and other folders you want to sync with that exist in Gmail) but not All Mail. Assuming you are using IMAP - Right click on the mail account name - subscribe - and see which Gmail folders you are subscribed to (those that Thunderbird will sync with). Uncheck All Mail in the list of folders you want to subscribe to. Try it carefully and when you have time - there may be a long resyncing process if you have a lot of stored email in Gmail. Also - re "Local Folders" - real local folders exist only on your own (local) computer/device, and are in a separate folder structure, not under the Gmail account. Once moved into a local folder, an email is saved on your computer. You may also have created folders that are under the Gmail account in Thunderbird - these are not saved locally, they do sync with Gmail, and if you are using IMAP they don't really exist on your computer. You may find more help on support.mozilla.org page for thunderbird-and-gmail Agnes

Thanks Agnes, I did not know that you can specify synchronization per folder. Your tip was very enlightening and useful.