Click the Settings link, located in the upper right corner of the webmail window.
In the left pane, click General Settings.
Click the Email Options tab.
In the Display Preferences section, select from the following options:
Display HTML emails—Indicate whether you want to view new email messages in HTML format by default.
Enable keyboard shortcuts—Keyboard shortcuts can be used to navigate and perform actions. Click the keyboard shortcuts link to view a list.
Preview pane—The preview pane enables you to view a selected email, without opening the email in its own window. By default, the preview pane will be available when you are viewing email folders. To change how the preview pane is displayed, click the drop-down menu and select Bottom,Right, or Do not display.
Number of messages listed per page—Indicate how many email messages you want to display in the email list at one time. If you are using a slow connection, you may prefer to display only a few email messages at a time (e.g., 10 or 20).