New Outlook for Windows becomes available for GCC High and DoD

New Outlook for Windows will be available for GCC High and DoD environments starting with Public Preview in July 2026 and General Availability from late September to December 2026. It remains off by default, opt-in, and admins control availability via registry keys and policies. Users can switch freely. What and Why: New Outlook for Windows will be available for U.S. Government clouds (GCC High and DoD sovereign environments). This milestone helps organizations move forward with adoption planning while maintaining administrative control. Rollout Schedule: Public Preview (GCC High and DoD): New Outlook will begin Public Preview in July 2026. General Availability (GCC High, DoD):  We will begin rolling out in late September 2026 and expect to complete by late December 2026. General Availability (DoD): We will begin rolling out in late September 2026 and expect to complete by late December 2026. Impact on Your Organization: Who is affected: GCC High and DoD tenants Exchange and Outlook admins Platforms/Services: New Outlook for Windows What will happen: Existing users who continue to use classic Outlook for Windows are not affected. New Outlook for Windows becomes available for GCC High and DoD sovereign environments but remains OFF by default. New Outlook continues to be an opt-in experience. Users can choose to switch to the new experience and can revert back to classic Outlook at any time. This update does not change organization settings and will not automatically switch users from classic Outlook for Windows. Microsoft will provide at least 12 months’ notice before initiating any Microsoft-driven migration steps in managed environments.  Learn more about how we are approaching our migration timeline: New Outlook for Windows: A Guide to Product Availability. General Availability status enables organizations to begin evaluating and planning adoption timelines for the new Outlook experience. A future announcement will provide General Availability details for additional sovereign cloud environments. Action Required / Recommendations: Administrative action is required to enable new Outlook for Windows in supported sovereign environments. The experience remains off by default. To enable new Outlook for Windows when it becomes available, set the appropriate registry key: Enable availability when ready: GCC High: […]

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