Starting mid-July 2024, legacy Outlook clients will be retired, affecting users with outdated versions on iOS, Android, Mac, and Windows Mail and Calendar applications. From mid-August, outdated browsers will receive an error on Outlook web. Users must update to the latest versions for continued functionality and support.
Applies to: Exchange Online · Microsoft 365 for the web · Microsoft 365 apps
Source: mc.merill.net — data via Merill Fernando's open archive (MIT).