I can only speak for Gmail, as that is a setting done on the website forGmail.

It's not GMail. I don't understand your answer. This is Thunderbird to which I'm referring.

Stop holding the shift key while deleting is all I have to offer. The keyboard shortcut to bypass the trash/deleted folder is to hold shift while the delete occurs. ie shift+Delete

But "Stop holding the shift key while deleting"? I've been doing that for years. Why all of a sudden does the trash folder come up empty? The folder is there but no e-mail are in it.

BTW, the trash folder only shows under "local folders". I don't know if that makes a difference. I think there used to be a trash folder somewhere else in the list of folders. Thanks.

My Gmail content was, if you were referring to a Gmail account there is a website setting that causes Thunderbird to delete immediately. Obviously, not relevant to your situation. On your comment, there are normally trash folders for each account.