New Outlook to replace Classic Outlook?

Question

Will the New Outlook replace the Classic Outlook? I.e. will the Classic Outlook be discontinued?

Answer 1

Hello JVB

Thank you for reaching out to Microsoft Q&A Forum.

Microsoft is gradually transitioning from Classic Outlook to the New Outlook for Windows. The shift follows Microsoft’s three‑stage rollout: Opt‑in > Opt‑out > Cutover. The New Outlook is already at General Availability, and Classic Outlook remains available during this transition.

What Microsoft has communicated publicly:

Beginning April 2026, Classic Outlook will enter its opt‑out phase, meaning the New Outlook will become the default experience for most users. However, users will still be able to switch back to Classic Outlook during this stage if needed. Classic Outlook is not discontinued yet, and Microsoft has not announced a final cutover date for home users. For customers using Classic Outlook through Microsoft 365 subscriptions with desktop apps or perpetual licenses such as Office LTSC, Microsoft will continue supporting Classic Outlook at least through 2029. This includes ongoing security updates and compatibility maintenance, ensuring organizations can continue using Classic Outlook safely during the transition period.

Migration stages include:

• Opt‑in (current phase): Users can try the New Outlook while still keeping access to Classic Outlook.
• Opt‑out (starting April 2026): The New Outlook becomes the default, but users may switch back to Classic Outlook temporarily.
• Cutover (future date, not yet announced): Classic Outlook will be fully retired for most users, and new installations will only include the New Outlook.

For more details, you can refer to Microsoft’s official guidance: Stages of migration to new Outlook for Windows - Microsoft Learn

You can continue using Classic Outlook for now, and Microsoft will provide ample notice before any final retirement.

Thank you for your understanding.

Answer 2

Yes, the New Outlook is set to replace Classic Outlook. Currently, the New Outlook for Windows is in the opt-in stage, meaning users can choose to switch to it. By August 1, 2024, the New Outlook will move out of preview and into General Availability (GA), at which point it will be on by default for new deployments. Eventually, in the cutover stage, users will not be able to switch back to Classic Outlook. However, existing installations of Classic Outlook will continue to be supported until at least 2029, allowing for a transition period for users and organizations.

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References:

• Stages of migration to new Outlook for Windows
• Deployment overview for the new Outlook for Windows