I have a number of folders and sub folders created in Local Folders. Some of those were used as a means of moving email content from one imap server to another. They include the usual inbox, drafts, sent, junk, trash. Structure includes 4 or 5 of such layouts. The problem, when I delete anything from a subfolder directly under Local folders, it does not end up in the Trash folder under Local folders, but rather in one of the trash folders of the above structure. https://i.imgur.com/cIr1bJY.png In this pic, items deleted from say pcpartspicker folder would end up in the yellow ttrash folder instead of the red Trash. Mind you, ttrash was previously called trash. It took me hours to narrow down what was happening until I realized somehow thunderbird was using one of trash folders multiple layers deep as its default local folders trash. The issue was fixed/worked around by renaming the sub trash folders to ttrash, so there was only one "Trash" folder under Local folders. This begs the question, how does one set the default local folders trash folder? With imap it's a configurable option, but I couldn't find anything for local folders. Should trash be considered a forbidden folder name?