To get messages stored in a folder on the server to show in Thunderbird, you need to get Thunderbird to subscribe to that folder. Right-click the account, select "Subscribe", re-select the appropriate account (if necessary) and tick the required checkboxes.

I usually try to discourage Thunderbird users from selecting the All Mail folder. What value do you expect to gain from it?

What happens when you try to delete your home-made folder? Any error messages?

Hi Zenos, I checked the "Subscribe" setting. All folders are ticked aso the All Mail. The reason that I want to see it is quite simpel. I checked the data in the Gmail database and there many messages that I never received because I set a filter to delete these messages when they come in but they all went to All Mail in the Gmail database. When I try to delete the folder nothing happens, no error message and the folder is still there. I created a subfolder All Mail for All Mail, same problem, cannot be deleted. I have a second email account in there, I don't rememeber how it got in there but is working for All Mail. When I check the properties there is a tab for Retention Policy, it does not exist in the second one where the data are ok. Best Regards Heinrich

Your "manually" created All Mail folder is not going to relate to the gmail All Mail folder. If that is what you subscribed to you wasted as much time as creating it in the first place. Subscribe is for seeing folders on the provider's server. If you are using IMAP then you should see all the folders on the gmail server including All Mail. Subscribe to that one.