The Reading window Options pull-down menu contains some options that are similar to those defined in the Main window Options menu and in the Composition window Options menu.
To see the Reading window Options menu choices, click the Options button or type Meta-O. The following menu appears:
The Options pull-down menu provides choices for customizing your Reading window. You can specify the number of columns to be displayed in the window, add various shortcut function buttons to the window to help speed the composition process, show headers that normally are not displayed, display MIME-encoded raw text, and re-read the mailcap file.