The Buttons ... option enables you to select a large number of shortcut function buttons to display in Ishmail's Reading window. These buttons help streamline your use of the mail interface. Instead of possibly navigating through several menu layers to get to the function you want to perform, you simply click the associated shortcut button.
You specify shortcut buttons for the Reading window in exactly the same way that you specify them for Ishmail's Main, Composition, or Comment on Application windows. The only difference is the type of shortcut functions you can select for a particular window.
When you click on the Buttons ... option, the Edit Custom Buttons dialog menu appears, in which you specify shortcut buttons for the window. The section entitled Specifying Custom Buttons provides detailed information on how to use the Edit Custom Buttons dialog menu.