Recently migrating from a MS mail client to Thunderbird, I'm used to working exclusively with what T'bird calls Unified Folders, rarely using the All Folders view. Junk and Trash can be deleted in their respective Unified Folders by doing a CTRL+A and the Delete key, but it makes me a bit nervous as this action could inadvertently be applied to the Unified Inbox or Sent folders as well. But a right-click and selection of Empty Folder at least makes one stop and think. I do miss the "Are you sure..." warnings that MS optionally provided; I wonder if there is an add-on that might provide that?