VSTO Outlook add-in example
with source code (VB.NET, C#)

Add-in Express Toys™ VSTO
for Microsoft Outlook


Add-in Express Toys VSTO is a free sample addin / plugin for Microsoft Outlook 2003, 2007 and 2010. The add-in gives you an example of how to create custom command bars for Outlook Explorer and Outlook Inspector, get access to Outlook objects and add custom option and property pages. Also, this add-in shows how to use Extended MAPI to avoid Microsoft Outlook security alerts.

This Outlook plug-in allows you to examine real Internet headers and the body of the selected message and adds two custom option pages to the Outlook Options Page window and an Outlook Folder Properties dialog box. The plugin is based on Add-in Express for Office and VSTO and developed in Visual Basic .NET (VB .NET) and C#.

How you can extend Outlook with Add-in Express for VSTO

Add-in Express for VSTO is a .NET object library purposed for building Outlook extensions in Visual Studio 2005 with VSTO 2005 Second Edition (SE) installed and Visual Studio 2008, 2010. It provides developers with plenty of new features for Outlook plug-in development, including Advanced Microsoft Outlook Regions, customization for option and property pages, shortcuts for the Microsoft Outlook Navigation Pane, event helpers for the Folders, Items and Item objects and much more.

With Add-in Express for VSTO you can:

  • Develop powerful COM addins for MS Outlook 2003, 2007 and Outlook 2010.
  • Add and customize Outlook toolbars, menus and pop-ups.
  • Customize Microsoft Outlook windows, views and forms with Advanced Outlook Form and View Regions.
  • Add new or customize existing tabs for the Microsoft Outlook 2007 Ribbon UI, build the Quick Access Toolbar and Office Menu for Microsoft Outlook 2007.
  • Create Explorer and Inspector-specific toolbars, customize Outlook 2007 Inspector ribbons with your own ribbon tabs.
  • Extend the Outlook Reading pane, Navigation pane and To-Do bar with custom forms.
  • Add new pages to the Outlook Options dialog box and to a Folder Properties window.
  • Add context-sensitivity to your command bars and commandbar controls, ribbon tabs, menus, and sub-menus. E.g. you can show your toolbars for specified Outlook folders, items or views.
  • Customize Outlook toolbar with any visual .NET controls, such as buttons, grids, labels, tree-views edit and combo boxes.

See how to get started with Outlook plug-ins in VSTO (VB.NET and C#).

Download sample Outlook add-in

1. Compiled binaries are not included in the setup package of the Add-in Express Toys VSTO. You need Add-in Express for Office and VSTO to compile this Outlook add-in.

2. All projects are created using Visual Studio 2005 with VSTO 2005 SE. When opened in the Visual Studio 2008, the projects will be automatically converted into the VS 2008 format.

Add-in Express Toys VSTO toolbar

Add-in Express Toys VSTO adds to Outlook a new folder specific toolbar with tree buttons.

Folder specific Outlook toolbar

The buttons are:

About button

Shows the About window

Custom Outlook button that shows Internet headers of a selected message

Shows internet headers of a selected message.

Outlook internet header of a selected message

Outlook button showing the body of a selected message

Shows the body of a selected message.

Outlook message content

Add-in Express Toys VSTO toolbar

This example of Outlook add-in adds a new inspector specific toolbar with one button.

Outlook inspector specific toolbar

Custom Outlook button sets the current message as unread

Sets the current message as unread.

Add-in Express Toys VSTO Option page

This sample Outlook plug-in adds to the Outlook Options dialog box menu a new option page.

Modified Outlook options page

Add-in Express Toys Folder Property page

Add-in Express Toys VSTO adds a new property page to an Outlook Folder Properties window.

Custom Outlook folder property page