Outlook add-ins are integrations built by third parties into Outlook using the new web technologies based platform. Outlook add-ins have three key aspects:
- The same add-in and business logic works across desktop Outlook for Windows and Mac, web (Office 365 and Outlook.com), and mobile.
- Outlook add-ins can be acquired from the Office store or side-loaded by end-users or administrators.
The Outlook items that support mail add-ins include email messages, meeting requests, responses and cancellations, and appointments. Each mail add-in defines the context in which it is available, including the types of items and if the user is reading or composing an item.
To learn more about Outlook add-ins, see Outlook add-ins.