What is the Mail Threads folder, and is it safe to delete it?
Mail Threads is actually a “view” of all your mail messages, grouped with their replies, so you can view an entire conversation at once. It also contains your calendar entries, to-dos, and drafts. If you delete any messages/items from this view (or if you delete the whole view), you are also deleting them from whatever folder they were originally in. So, be very careful not to delete Mail Threads or any of its contents.
