Dragging multiple emails to DT does work, but there are a couple of things to be aware of. In my testing, dragging multiple emails to the DT icon in the Dock does not appear to work at all. Also, as I’ve tried various scenarios to help uncover an issue in this thread, I’ve seen some inconsistencies when dragging multiple emails to the Sorter. The most reliable method I have found, other than using the excellent plug-in included with Pro Office, is to select the emails in Mail, begin to drag them, then switch to DT using Command-tab, and drop them in the desired group in a DT window.