Using the Scroll Bar (Paned Style)

  A scroll bar lets you see text that cannot fit in one window
  region.

  Click on the up and down arrows at each end of the scroll
  bar to move through the text one line at a time.

  To move through larger amounts of text, use the slider in
  the center of the scroll bar.  The size and location of the slider
  indicates your position in the text.  A small slider at the top
  of the scroll bar indicates you are at the beginning of a large
  piece of text.  A large slider that fills the scroll bar indicates
  that you are viewing the entire body of the text.

  To move to another portion of the text, press MB1 in the
  slider region, drag the slider to an area representing the area
  of text to be displayed, and release MB1.  For example, to
  move to the last portion of the text, drag the slider to the
  bottom of the scroll bar and release MB1.

  Additional topics:

  *   Overview of Mail