If you use Mail and its preview pane to read your messages, you’ve probably noticed some odd behavior with a couple of often-used keys (or if you read Daring Fireball, where this issue was recently discussed). If you’re looking at a list of messages (and the list is active, i.e. you’ve clicked a message in the list), and you press the Up or Down Arrow key on the keyboard, Mail will select the previous or next message in the message list. That’s probably exactly what you’d expect to happen. If you press Page Up or Page Down, however, the message list will not jump up or down a full page—it won’t, in fact, move at all. That’s because Mail sends the Page Up and Page Down keystrokes to the message preview panel, not to the message list.
On one level, this makes sense—you can read lengthy messages in the preview panel and browse your list of messages with the keyboard, without having to switch the focus from one section to the other. On the other hand, it’s inconsistent—why is one set of keystrokes sent to one panel while another goes elsewhere? And if you want to move the message list by more than a message at a time, it seems you have to resort to the mouse and drag on the scroll bar.
Thankfully, someone at Apple thought this was a bit odd, too, and included a workaround of sorts. If you press and hold Control, then press Page Up or Page Down, the message list will move up or down a page at a time. This solution has existed for quite a while; it was first documented (to the best of my knowledge) back in December of 2004 in MacInTouch’s Mail.app special report by Jason Staloff. The recent mention on Daring Fireball, however, made me realize I’d never covered the solution here on Macworld.
Keep in mind that moving the message list view a page at a time doesn’t change the selected message, so the preview panel won’t change. If you want to preview a different message, you’ll need to use the arrow keys (or the mouse) to change the selection. If you use the arrow keys, Mail will jump the message list view back to your current selection, so you’d then have to scroll through everything you’d just jumped over—so in this case, the easiest thing to do is reach for the mouse after using the Control and Page Down/Up key, then click the message you wish to preview.