Outlook and OWA users will soon see a banner notification to recommend the installation of an Edge extension. The extension logs into the user account to peek into the mailbox, calendar, tasks, and contacts. Tenant administrators have until July 30 to decide if they will block the display of the banners. This can be done using the Office Cloud Policy Service or a Group Policy Object.
https://office365itpros.com/2021/07/09/outlook-edge-extension-coming-soon/
