RM565861 - Outlook: S/MIME support for Shared Mailboxes and Delegate Mailboxes in New Outlook for Windows

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

GA date: July CY2026