While everyone probably sets the option in the email settings to “Save copy of sent messages to “Sent” folder”, it is sometimes useful not to use it. For instance, I sometimes send files to myself from home to the office, or to my own private email account to download it on another device. In these cases, it would be nice to have the option to deviate from the email settings just by selecting “Send without saving” in the message composition window. It could be an option in the drop-down menu of the “Send” button, where you can now select “Send as mass mail” or “Send later”, or it could be an icon in the icon bar of the message composition window.