Summary
Details
Updated February 20, 2026: We have updated the timeline. Thank you for your patience.
[Introduction]
Microsoft is updating the opt‑out phase start date for new Outlook for Windows in Enterprise environments from April 2026 to March 2027.
[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?
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 timeline and providing 12 months of lead time as we continue delivering key features and improvements.
[How this affects your organization:]
Who is affected:
- Microsoft 365 administrators managing Outlook for Windows.
- Users of classic Outlook for Windows.
- Organizations that previously disabled the new Outlook toggle or have not yet begun migration planning.
What will happen:
- Migrated users will receive in‑app onboarding prompts and can switch back to classic Outlook if 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 migrated if one or more of the following is true:
- You have opted out users using the Policy of automatic migration
- New Outlook toggle is hidden via policy
- Perpetual license is in use
- On premise account
[What you can do to prepare:]
Prepare your organization for the opt-out phase that will begin 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 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 transition effectively. Refer to the following resources 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 roll 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 in 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 be presented with a user-friendly onboarding experience and 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]
| Question | Explanation |
|---|---|
| Does the change include an admin control? | Admins can manage the change using the policy for automatic migration and existing Outlook policies. |
| Can the change be controlled through Entra ID group membership? | Migration can be scoped to specific users or groups using Entra ID group targeting. |
| Does the change allow a user to enable and disable the feature themselves? | Users moved to new Outlook can switch back to classic Outlook during the transition period. |
Change History
We're making some changes to the migration from classic Outlook to new Outlook for Windows.
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:]
General Availability (Worldwide): We will begin rolling out April 2026.
[How this will affect your organization:]
You are receiving this message because our reporting indicates one or more users in your organization are using Microsoft 365 Enterprise licenses.
Users will have notice in 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 can toggle back to classic Outlook if they choose to.
Users will not be toggled if one or more of the following is true:
- You have opted your users out of being automatically toggled per Admin-Controlled Migration to New Outlook
- 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 to do to prepare:]
This rollout will happen automatically with no admin action required starting April 2026. You may want to notify your users about this change and update any relevant documentation as appropriate. When this change takes effect, if you choose to exclude users from the experience, you can use the following Admin policy to manage new Outlook migration: Admin-Controlled Migration to New Outlook
Later, this policy will also be available via Group Policy Objects (GPO), Cloud Policy, and Intune.
Updated February 20, 2026: We have updated the timeline. Thank you for your patience.
[Introduction]
Microsoft is updating the opt‑out phase start date for new Outlook for Windows in Enterprise environments from April 2026 to March 2027.
[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?
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 timeline and providing 12 months of lead time as we continue delivering key features and improvements.
[How this affects your organization:]
Who is affected:
- Microsoft 365 administrators managing Outlook for Windows.
- Users of classic Outlook for Windows.
- Organizations that previously disabled the new Outlook toggle or have not yet begun migration planning.
What will happen:
- Migrated users will receive in‑app onboarding prompts and can switch back to classic Outlook if 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 migrated if one or more of the following is true:
- You have opted out users using the Policy of automatic migration
- New Outlook toggle is hidden via policy
- Perpetual license is in use
- On premise account
[What you can do to prepare:]
Prepare your organization for the opt-out phase that will begin 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 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 transition effectively. Refer to the following resources 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 roll 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 in 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 be presented with a user-friendly onboarding experience and 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]
| Question | Explanation |
|---|---|
| Does the change include an admin control? | Admins can manage the change using the policy for automatic migration and existing Outlook policies. |
| Can the change be controlled through Entra ID group membership? | Migration can be scoped to specific users or groups using Entra ID group targeting. |
| Does the change allow a user to enable and disable the feature themselves? | Users moved to new Outlook can switch back to classic Outlook during the transition period. |
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