With this visual RAD toolkit you can easily develop secure, managed, isolated and deployable plugins for Outlook Express on Windows Mail.
Add-in Express provides Outlook Express with a unified extensibility model based on familiar interfaces and objects of the Microsoft Office and Outlook, and gives you visual designers for advanced customization of Outlook Express menus and toolbars. It allows adding custom menu items to the main Outlook Express menu and Inspector menu; using custom controls such as simple buttons, pop-up, dropdown, split buttons and separators on your toolbars; embedding custom forms into the main Outlook Express window and any e-mail windows; creating view and form regions for the main Outlook Express window, mail compose and mail read windows and more.
Another key benefit of Add-in Express is that it makes your Outlook Express plug-ins version neutral, i.e. you write your code once and have it work across Outlook Express 6 on Windows 2000 and XP through Windows Mail on Vista. Add-in Express directly supports Visual Basic .NET (VB .NET), Visual C#, and C++ in Visual Studio 2003 and 2005, as well as RemObjects Chrome.
For more information please visit: http://www.add-in-express.com/programming-outlook-express/