New Outlook Relies on Web and Edge

The new Outlook architecture has advantages for Microsoft and for developers who want to extend Outlook, but it might never be supported on Exchange Server. The accompanying diagram (fig. 1) shows a simplified view of new Outlook’s major components.

A service based on Outlook on the Web (left), the Web interface of Exchange Online, provides the logic and much of the user interface of new Outlook. A native client application (right) browses the service and presents the interface to the user, using Edge WebView2, an embedded browser library. The client also writes files or performs other tasks that require native application capabilities.

With this new architecture, Microsoft can rapidly roll out new features and fixes to all users and share much of the codebase across Outlook client platforms and the Web. Developers inside and outside Microsoft can extend the new apps with standard Web development technologies (such as JavaScript and the ReactJS framework), so projects start with a base of trained Web developers to draw on.