MC1246031 – M365 Change Digest

One-line summary

Copilot Chat and features like Summarize and Draft are now available in shared and delegated mailboxes in Outlook (except classic), for Copilot-licensed users, enhancing team productivity and permissions support.

Similar updates

Details

RoadmapIds

554936

Summary

Microsoft is expanding Copilot Chat in Outlook to support shared and delegated mailboxes across new Outlook versions starting early April 2026. Users with Microsoft 365 Copilot licenses can use Copilot features directly in these mailboxes, improving team collaboration without extra setup or mailbox-specific prompts.

Platforms

Web

Body (from Message Center)

Updated May 1, 2026: We have updated the content. Thank you for your patience.

[Introduction]

This feature is rolling out to new Outlook for Windows, Outlook on the web, Outlook for Mac, and Outlook for iOS and Android. It is not yet available in classic Outlook for Windows. We’ll share an update when support is added.

We are expanding Microsoft Copilot capabilities in Outlook to include shared and delegate mailboxes. This update allows users who already have access to Microsoft 365 Copilot to use Copilot features, including Copilot Chat, directly while working in shared or delegated mailboxes. This change is designed to improve productivity for teams that collaborate using shared inboxes such as executive assistants, support desks, HR, and finance teams.

This message is associated with Microsoft 365 Roadmap ID 554936.

[When this will happen:]

Targeted Release: We will begin rolling out early April 2026 and expect to complete by early May 2026.
General Availability: We will begin rolling out early May 2026 and expect to complete by early June 2026.

[How this affects your organization:]

Who is affected:

Users who have access to shared or delegated mailboxes in Outlook
Organizations where users are licensed for Microsoft 365 Copilot

What will happen:

Users can access Copilot Chat in Outlook directly while working in a shared or delegated mailbox, rather than only from their primary mailbox.
Copilot features such as Summarize and Draft will work in shared and delegated mailboxes.
Support includes full-access shared mailboxes as well as shared folder permissions.
Users no longer need to include mailbox-specific phrases (for example, “in <mailbox>@domain.com”) when prompting Copilot. Prompts can be written as if the mailbox were their own, and responses are grounded in the active shared mailbox.
Folder-level permissions are supported for accessing Copilot Chat in shared and delegated mailboxes.
Copilot conversation history is saved to the user’s primary account, ensuring there is no sharing of conversation history between users who access the same shared mailbox.

[What you can do to prepare:]

No action is required to enable this feature.

Review shared and delegated mailbox permission models, including folder-level permissions, to ensure they align with your organization’s expectations.
Inform users that Copilot conversation history remains associated with their primary account, even when Copilot is used from a shared mailbox.
Update internal documentation or training materials to reflect that Copilot can now be used directly within shared and delegated mailboxes in Outlook for eligible users.

[Compliance considerations:]

Question	Explanation
Does the change alter how existing customer data is processed, stored, or accessed?	Copilot Chat in Outlook can now process and ground responses using email and folder content from shared and delegated mailboxes more seamlessly using the mailbox permissions assigned to the user.
Does the change introduce or significantly modify AI/ML or agent capabilities that interact with customer data?	Microsoft Copilot capabilities, including Copilot Chat, Summarize, and Draft, are now available in the context of shared and delegated mailboxes in Outlook.
Does the change provide end users a new way of interacting with generative AI?	Users can now interact with Copilot Chat directly while working in shared and delegated mailboxes, without switching back to their primary mailbox.

Raw JSON (for debugging)

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