On the View tab, in the Layout group, select Reading Pane in the ribbon, and then select Off. Selecting Off closes the Reading Pane only for the folder you’re in. To turn off the Reading Pane quickly for multiple folders, on the View tab, select Change View > Apply Current View to Other Mail Folders, and then choose folders in the Apply View dialog box.

To turn the Reading Pane ON or to MOVE it:    

On the View tab, in the Layout group, select Reading Pane, and then select Right or Bottom.


Reading Pane Options:

On the View tab, in the Layout group, select Reading Pane in the ribbon, and then select Options.