Message thread display options

Normally, the thread for the message you are viewing is displayed below the message.  If you enable auto-hide message threads in your account preferences (located at "preferences => account" in your menu bar), then then message thread will auto-hide to the left of the message itself.  To display the thread, either click on "view thread" in the message nav bar (below the menu bar), or hover over the "message thread" graphic to the left of the message.