Just to clarify a point. There is no 'preview' pane. When you select to read a message in either the 'Message Pane' or a new tag or a new window, the email is opened; you do not see a 'preview'. Make sure the 'Message Pane' has been selected via 'Mail Toolbar' toolbar: 'Menu icon ' > 'Options' > 'Layout' > select 'Message Pane' or via 'Menu Bar' toolbar: 'View' > 'Layout' > select 'Message Pane' I think you may be trying a bit too hard to get this correct and maybe you are releasing the left click before moving upwards. Once you have grabbed the arrow using the left click hold down , it does not matter if you waver a bit providing you do not release the left click hold down. So read through instructions below and retry. re :Left clicking showed the up/down arrows. At this point in time, it does not require any left clicking to display the double headed arrow. All you need to do is move the mouse cursor to hover over the top edge and the double headed arrow will auto appear when in the correct place. When you see the double headed arrow appear denoting the top edge, this is now the time to use left click and hold it down to grab it. Do not release the left click, keep it held down and now just move upwards. Then release the mouse - release the left click.