Create Outlook add-ins for compose forms

Starting with version 1.1 of the schema for Office Add-ins manifests and v1.1 of Office.js, you can create compose add-ins, which are Outlook add-ins activated in compose forms. In contrast with read add-ins (Outlook add-ins that are activated in read mode when a user is viewing a message or appointment), compose add-ins are available in the following user scenarios:

  • Composing a new message, meeting request, or appointment in a compose form.

  • Viewing or editing an existing appointment, or meeting item in which the user is the organizer.


    If the user is on the RTM release of Outlook 2013 and Exchange 2013 and is viewing a meeting item organized by the user, the user can find read add-ins available. Starting in the Office 2013 SP1 release, there's a change such that in the same scenario, only compose add-ins can activate and be available.

  • Composing an inline response message or replying to a message in a separate compose form.

  • Editing a response (Accept, Tentative, or Decline) to a meeting request or meeting item.

  • Proposing a new time for a meeting item.

  • Forwarding or replying to a meeting request or meeting item.

In each of these compose scenarios, any add-in command buttons defined by the add-in are shown. For older add-ins that do not implement add-in commands, users can choose Office Add-ins in the ribbon to open the add-in selection pane, and then choose and start a compose add-in. The following figure shows add-in commands in a compose form.

Shows an Outlook compose form with add-in commands.

The following figure shows the add-in selection pane consisting of two compose add-ins that do not implement add-in commands, activated when the user is composing an inline reply in Outlook.

Templates mail app activated for composed item

Types of add-ins available in compose mode

Compose add-ins are implemented as Add-in commands for Outlook. To activate add-ins for composing email or meeting responses, add-ins include a MessageComposeCommandSurface extension point element in the manifest. To activate add-ins for composing or editing appointments or meetings where the user is the organizer, add-ins include a AppointmentOrganizerCommandSurface extension point element.


Add-ins developed for servers or clients that do not support add-in commands use activation rules in a Rule element contained in the OfficeApp element. Unless the add-in is being specifically developed for older clients and servers, new add-ins should use add-in commands.

API features available to compose add-ins

See also