I have noticed that, when I drag-and-drop (or using Edit > Move to Folder) to move messages from one public folder to another, it copies the message, rather than moving it. This is not the case when moving messages within personal folders or Outlook folders. Part of my job is to distribute mail from a central public folder for our department to other subfolders in that public folder, and having to move, then delete, each message is a pain. I can hold the SHIFT key when performing a drag-and-drop to make this work, but is there a setting somewhere to make this behavior default?