MC949965 - Toggle to new Outlook

We're making some changes toUpdated February 20, 2026: We have updated the migration from classic Outlook totimeline. Thank you for your patience. 

Introduction

Microsoft is updating the opt‑out phase start date for new Outlook for Windows. Windows in Enterprise environments from April 2026 to March 2027.

We aim to give more than 12 months of notice to help our customers prepare. Starting April 2026, users with Microsoft 365 for Enterprise licenses will be toggled from classic Outlook for Windows to new Outlook for Windows. Users will be toggled into new Outlook once with this roll-out, with potential to be toggled again in the future. Users will maintain the ability to go back to and use classic Outlook.

Our goal with this change is to give users an opportunity to try new Outlook as millions of users already have. New Outlook gives users the most modern experience with Copilot features, theming, and a wave of valuable time-saving features like Pinning and Snoozing mails. Users are also welcome to give us feedback on new Outlook using Feedback in the Help ribbon, so we can tailor the best email and calendar experience.

When this will happen:

• The opt‑out phase for Enterprise environments will now begin in March 2027 (previously April 2026), providing organizations with 12 months of lead time to prepare. 
• GCC High and DoD timelines will be communicated separately at a later date.

Why is there a change to the timeline?

General Availability (Worldwide): We will begin rolling We’re seeing strong and accelerating adoption of new Outlook as organizations progress on timelines that match their readiness. At the same time, we continue to invest heavily in expanding capabilities and addressing feedback from customers who want to go further with new Outlook. To ensure organizations have the time they need to prepare—and to fully realize the value of ongoing innovation—we’re extending the opt-out April 2026. timeline and providing 12 months of lead time as we continue delivering key features and improvements.

How this will affectaffects your organization:

You are receiving this message because our reporting indicates one or more users in your organization are using Who is affected:

• Microsoft 365 Enterprise licenses.

  administrators managing Outlook for Windows.

• Users will have notice inof classic Outlook for Windows.
• Organizations that previously disabled the application prior to being toggled and will have the option to opt out of the experience in Outlook Options > General. Users who are toggled into new Outlook toggle or have not yet begun migration planning.

What will happen:

• Migrated users will receive in‑app onboarding prompts and can toggleswitch back to classic Outlook if they choose to.

  needed.

• Existing policies that disable or limit access to new Outlook will remain in effect.
• Admins can continue using Admin‑controlled migration to move users in a staged, reversible manner ahead of time.
• Users will not be toggledmigrated if one or more of the following is true:
  • You have opted yourout users out of being automatically toggled per Admin-Controlled Migration to New Outlookusing the Policy of automatic migration
  • New Outlook toggle is hidden via policy
  • Perpetual license is in use
  • On premise account

User-facing article: Switch to new Outlook for Windows - Microsoft Support. We will continue to update this article as we get closer to April 2026.

What you need tocan do to prepare:

This rolloutPrepare your organization for the opt-out phase that will happen automaticallybegin March 2027. Evaluate and use the Admin-controlled migration policy to the stage and schedule that is right for your organization.

Take preparatory steps to:

• Assess feature and web add-in readiness.
• Conduct any needed pilots.
• Build a timeline that works for your organization.
• Re-enable the toggle if previously disabled and enable the Admin-controlled migration policy to move forward.

Be sure to communicate with no admin action required starting April 2026. You may want to notify your users about what to expect, and leverage Microsoft’s adoption resources to make the experience smooth.

Resources and Support:

Microsoft is committed to helping you manage this change and update any relevant documentation as appropriate. When this change takes effect, if you choosetransition effectively. Refer to exclude users from the experience, you can use the following Adminresources for detailed guidance and tools:

• Adoption Kit: A downloadable kit with checklists, project planning templates, user communication examples, and FAQs to support your rollout. New Microsoft Outlook for Windows – Microsoft Adoption.
• Tips for new users: Start new users in new Outlook | Microsoft Learn.
• Control installation and use: If you have previously disabled the new Outlook toggle via policy and now want to manageroll out new Outlook. Control installation and use of new Outlook | Microsoft Learn.
• Policy for Admin-controlled migration: This policy allows you to toggle users into new Outlook migration: Admin-Controlled Migration to New Outlook

  Later, thisin a controlled manner, with in-app prompts that ease users into the new experience over successive Outlook launches. Users who are moved by policy will also be available via Group Policy Objects (GPO), Cloud Policy,presented with a user-friendly onboarding experience and Intune.will have the option to switch back to classic Outlook. Microsoft recommends starting with new users in your organizations and those piloting and using Copilot as early target audiences. Policy for Admin-Controlled Migration to new Outlook for Windows | Microsoft Learn; User-facing article.

Compliance considerations