C# and VB.NET Outlook addin sample

Add-in Express Toys™ .NET
for Microsoft Outlook

Add-in Express Toys .NET is a free sample Outlook add-in that adds two useful features to Microsoft Outlook. This plugin allows you to examine real Internet headers and the body of the selected message. The add-in shows how to create custom command bars and ribbon tabs for Outlook Explorer and Inspector windows, get access to Outlook objects and add custom option and property pages. Also, the addin demonstrates how to use Extended MAPI to avoid security alerts.

The plugin is based on Add-in Express for Office and .NET and developed in Visual Basic .NET (VB .NET) and C#.

How Add-in Express can extend Outlook with custom functionality

Add-in Express for Office and .NET is a .NET object library developed specially for creating Outlook plug-ins using Visual Studio. It can help you avoid the complexities of Office's ActiveX interfaces and low-level programming. With Add-in Express you can:

  • Develop COM addins for MS Outlook 2021/365 - 2000.
  • Create Explorer and Inspector-specific toolbars and ribbons.
  • Control all built-in command bars including context-sensitive pop-ups.
  • Add new or customize existing tabs for the Ribbon UI.
  • Customize Microsoft Outlook windows, views and forms with Advanced form and view regions.
  • Build the Quick Access Toolbar and Office Menu.
  • Customize the Backstage View.
  • Develop custom task panes.
  • Extend the Reading pane, Navigation pane and To-Do bar with custom forms.
  • Add new pages to the Options dialog box and to the Properties window for any folders and more.

Add-in Express provides one entry point to access Outlook objects and events. It supports VB.NET, Managed C++ and C#. Find more about special features for Outlook plug-in development in .NET.

Download sample Outlook add-in

Note. Compiled binaries are not included in the packages of Add-in Express Toys containing the source code. You need Add-in Express for Office and .NET to compile this sample Outlook add-in.

Custom toolbar / ribbon tab added to Outlook Explorer

This sample Outlook addin adds a new toolbar or ribbon tab with tree buttons to the Explorer window.

Custom Outlook toolbar

Custom tab on the Outlook ribbon

The buttons are:

Shows the About window.

Shows the About window of the Add-in Express Toys add-in.

The button that shows Internet headers of a selected message

Shows internet headers of a selected message.

Outlook internet header

The button shows the body of a selected message

Safely shows the body of a selected message in the plain text format.

Outlook message content

Custom toolbar / ribbon tab added to Outlook Inspector

A new toolbar or a ribbon tab with one button is added to the mail item window.

A button on the Outlook inspector toolbar that marks the current message as unread

A custom ribbon button that marks the current message as unread

A custom Option page

This sample Outlook plug-in adds a new option page.

Customized Outlook options page

A custom Folder Property page

A new property page is added to the Inbox folder properties.

Newly added Outlook folder property page