Change the font or font size of the message list
The message list appears between the Navigation Pane and Reading Pane in Microsoft Office Outlook 2007. The default font setting is Segoe UI regular 8-point.
You can customize the font and its appearance. For example, you can change message list to use an alternate font or a smaller or larger font size.
In Mail, on the View menu, point to Current View, and then click Customize Current View.
Tip To open the Customize View: Messages dialog box, right-click the message list heading where Arranged By appears, and then click Custom.
Click Other Settings.
Under Column Headers and Rows, click Row Font.
Click a font, font style, and size that you want to use.
On the Font, Other Settings, and Customize View: Messages dialog boxes, click OK.