Dragging Emails to Folders and Sub-folders. It would be a nice enhancement to require hovering over a folder before the sub-folders underneath it are expanded. Since expansion is more or less immediate, it just requires another action on my part to contract those to make for a "clean" non-expanded folder list. Also, hovering over a folder with sub-folders before it's expanded would alleviate "accidental/unintended" expansion while moving your cursor around and briefly selecting a folder of non-interest.