When inserting an attachment, allow users to cut the filename from the Recent Items list to paste into the subject line.
In Outlook 2010, while inserting an attachment from File Manager, I could cut the filename (without the extension; thumbs up) and paste it in the subject line, then go back and insert the attachment.
With 2016, I LOVE the Recent items list, when attaching a file, but have no way of cutting the filename to paste it into the subject line. I have to attach the Recent file, then save as, and cut it from that dialogue box. Then I paste it into the subject line and backspace through the extension info.