M365 Changelog: Control inbox and calendar sharing options in Outlook mobile

MC661223 – Outlook mobile users can give author, editor, and reviewer permissions to their inbox from the mobile experience.

They can also give view, edit, and delegate permissions to their calendar.

This message is associated with Microsoft 365 Roadmap ID 146733

When this will happen:

Standard Release: Microsoft will begin rolling out early August and expect to complete by end of August. 

How thus will affect your organization:

Starting at the beginning of August, tenant admins will be able to turn off the ability for users to share their inboxes and calendars with the above permissions from Outlook mobile using app configuration values.

When the app config value is turned on, the user experience is as follows:

  • Under the “Share Your Inbox” settings, users will have “Add People” greyed out. Users that have already shared their inboxes will have their delegates listed here.
  • Under the “Share” option in calendar settings, users will have “Add People” greyed out. Users that have already shared their calendar will have their delegates listed here.

Blocking sharing is limited to the sharing entry points in settings for mail and calendar in Outlook mobile. All other sharing entry points, like share sheets, compose forwarding, etc. are not affected with this feature. The addition of shared and delegate mailboxes are also not affected. Users who have already been added to a shared mailbox or as delegates to an inbox or calendar will still be able to add those to their Outlook mobile experience. 

This new capability is off by default.

App Configuration Keys

The app Configuration keys used to control this experience are: 

  • For mail: com.microsoft.outlook.Mail.Blocksharing 
  • For calendar: com.microsoft.outlook.Calendar.Blocksharing 

What you need to do to prepare:

If admins wish to continue to allow users to delegate their inboxes and calendars, no action is necessary. 

For more information on app configuration keys, please visit: Deploying Outlook for iOS and Android app configuration settings in Exchange Online | Microsoft Learn 

Additional information