Create Outlook form regions in C#, VB.NET

Add-in Express™ Regions
for Microsoft® Outlook® and VSTO

Outlook form regions based on Add-in Express

Sample form regions

Outlook form regions are essentially sub-panes that can be docked in the window for any Outlook item (also known as an Inspector window) for both read and compose modes. All item types such as Mail, Task, Contact and Appointment are supported with Add-in Express Regions. An advanced region can be docked to any side of the Inspector window and will work equally well under Outlook 2021, 2019, 2016, 2013, 2010, 2007 and 2003.

Outlook form regions are implemented using the concepts detailed extensively on the Basic concepts page. In summary, your advanced form regions:

  • Are shared by all loaded add-ins and may host several forms at the same time
  • Include a region header which helps users to navigate between hosted forms; you can disable the header
  • Can be resized by users, or you can prevent them from resizing the region at all
  • Can be hidden or minimized by users; you can completely control their state
  • Can be dragged between docks; you can disable this ability completely or specify the supported docking locations
  • Can be bound to specific Outlook Inspector types, message classes or Inspector modes (read or compose)

Finally, when the user closes Outlook, advanced Add-in Express form regions stores the state, size and position for each region, and restores all settings for the next Outlook session.

Complete replacement for Outlook Inspector

A sample region completely replaces all Inspector pages

With Advanced Outlook Form Regions you can completely replace all pages of any Inspector window. The standard Replace All Form Region types were introduced in Outlook 2007 and are also available in later versions, but are still not supported for Outlook 2003. Add-in Express Regions, however, do support all versions of Outlook 2003 through 2021, and are very easy to implement. You can bind your replace all regions to specific folders, inspector types, message classes or inspector modes.

On-demand Outlook form regions

Even better, Add-in Express form regions provide a new kind of region: on-demand regions. This region type allows you to embed your forms under all pages of the Inspector window and the user can display them whenever they want to. Like all other regions based on Add-in Express, the on-demand Outlook form region can be bound to specific folders, inspector types, message classes or inspector modes.