As a mac newbie, I am learning the keyboard and navigation. I have been heavily keyboard-oriented and prefer a keyboard shortcut when they are available. I have looked around for some but am unable to find them. It seems that some things just require the mouse. An example would be navigating the mailboxes in Mail. Seems there is no keystroke to move up and down to select a mailbox, nor to "expand all" in the mailboxes pane. Instead each flippy triangle has to be clicked, which is quite tedious during my mail conversion process. Are there any shortcuts for these actions?