Chilton Preview for Microsoft Outlook is an add-in for Outlook that adds a preview window for e-mail messages.

Microsoft Outlook's AutoPreview lets you see just the first three lines of messages. This tiny add-on puts a whole third pane on your Outlook window, to let you scroll through entire messages without opening them. It also optionally displays the To:/Cc: recipients. You can copy text from the preview pane, adjust the display font, and click on Internet URLs and e-mail addresses to launch your browser or a new mail message. File attachments can be opened or saved when applicable.