This pane contains the list of your message folders (other email programs may call them mailboxes). To select a folder, simply click on it. The messages contained in the folder will now appear in the Headers pane. The folder list can be displayed in both a short view, which takes up only a small portion of the left side of the screen, and a long view, which takes up the entire left side of the screen but is able to show more mailboxes. You can toggle between these two views under Appearance/Layout in the Settings->Configure KMail... dialog. Also see the Folders Section for more information about how to use folders.

This pane lists header information (message Status Flags, Sender, Subject, Date, and other optional columns like Size, Attachment Flag, Important Flag, etc.) for the messages in the currently selected folder. Clicking on a header will select that message and display it in the Message pane; you can also select more than one message by holding down the Ctrl key when clicking on messages. You may sort the messages by clicking on the column that you wish to sort; if you click on the same column more than once, sort order will toggle between ascending/descending and some alternative sorting criteria will become available (like sorting by Status when you click on the header of the Subject column). Clicking the right mousebutton on the list header shows a popup menu, which allows to show or hide several columns in the list.

This pane displays the currently selected message. Attachments appear at the bottom of the message, either as icons or embedded in the message, depending on View->Attachments. For complex messages the structure of the message is shown in the message structure viewer below the preview pane. The placement of the preview pane as well as the placement of the structure viewer can be changed under Appearance/Layout in the Settings->Configure KMail... dialog. Moreover, you can disable the preview pane and you can choose when the message structure viewer should be shown. You can scroll through the message page-by-page using the Page Up and Page down keys, or line-by-line using the up arrow and down arrow keys; you can also use key shortcuts to skip through your messages without having to use the mouse.