Microsoft Outlook gives you the ability to write macros to control Outlook using Visual Basic for Applications (VBA). You use the same Visual Basic Editor that’s available to other Microsoft Office applications, giving you a powerful, yet easy-to-use environment in which to customize and extend Outlook.
Visual Basic for Applications macros are the ideal solution when you want to customize Outlook but don't need to develop custom forms. You can easily create a toolbar button that runs a macro by using the toolbar-customization features of Outlook.