Ribbon.xml

<?xml version="1.0" encoding="UTF-8"?>
<customUI onLoad="Ribbon_Load" xmlns="http://schemas.microsoft.com/office/2006/01/customui">
	<ribbon>
		<tabs>
			<tab idMso="TabMail">
				<group id="FileMessage" label="Mail Sorter">
					<button id="FileMessageButton" onAction="FileMessage_OnClick" imageMso="MoveItem" label="File Message" screentip="Move the message to the Sender's folder." size="large" />
				</group>
			</tab>
		</tabs>
	</ribbon>
</customUI>