Microsoft 365 Roadmap

Outlook
S/MIME support for Shared Mailboxes and Delegate Mailboxes in New Outlook for Windows

Feature details and release plans from a build snapshot of Microsoft's official roadmap feed.

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Product
Outlook
Release status
In development
RSS publication

Feature overview

New Outlook for Windows will extend S/MIME support to shared mailboxes and delegate mailboxes associated with a user's primary account. Users will be able to sign, encrypt, decrypt, and reply to S/MIME-protected messages while working from shared and delegated mailboxes. #newoutlookforwindows

Expected release date

July CY2026

Source: Microsoft 365 Roadmap RSS (build snapshot) Feature ID: 565861

RSS snapshot built . Refreshed on rebuild and deployment.

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