Mail preview pane hide/show

The message preview area in Mail shows the contents of the selected message. In El Capitan (10.11) the preview pane is shown to the right of the message list. In the earlier OS (or if the classic mode is enabled in El Capitan) the preview pane is shown below the message list.

To hide preview pane:

• In El Capitan
  • Move your cursor to the divider line between the right edge of the message list and the preview pane.
  • Drag the divider line to the right until the preview pane disappears.
• In earlier versions of Mac OS X or if the classic mode is enabled in El Capitan
  • Move your cursor to the divider line between the bottom edge of the message list and the preview pane.
  • Drag the divider line down until the preview pane disappears.

To re-enable the preview pane:

• In El Capitan
  • Move your cursor to the right edge of the message list.
  • Drag the divider line to the left until the preview pane disappears.
• In earlier versions of Mac OS X or if the classic mode is enabled in El Capitan
  • Move your cursor to the bottom edge of the message list.
  • Drag the divider line up until the preview pane disappears.
• If the above process for revealing the preview pane does not work, do the following:
  1. Quit Mail
  2. Move ~/Library/Containers/com.apple.mail to the desktop.
  3. Restart Mail
  4. If Mail is working properly, delete the com.apple.mail that you had previously moved to the desktop.