MC376710 – Some users can access an unsupported early test version of the new Outlook for Windows (archived)

Product:

Exchange, Microsoft 365 Apps, Outlook, SharePoint

Platform:

Online, Web, World tenant

Status:

Change type:

New feature, User impact, Admin impact

Links:

Details:

We are aware that some users can access an unsupported early test version of the new Outlook for Windows. This version is missing some of the features and enhancements that will be available later for our customers in the Beta Channel. We encourage our customers to wait for the beta version to be released.
We recognize the need for tenants to control access to apps in their organizations, so we are releasing early the instructions to do so. We expect to provide more news in the coming weeks about our Beta release. If you would like to block your users from connecting their Microsoft 365 accounts associated with your organization to this new app, please follow the PowerShell instructions. When the beta is available you will need to unblock them using the same instructions.
These instructions prevent the account from syncing to the new Outlook but do not prevent download.
To enable/disable access for a single user:
Run the PowerShell app as an administrator
Input: Connect-ExchangeOnline -UserPrincipalName
Input: set-CASMailbox -OneWinNativeOutlookEnabled <$true> if enabling or <$false> if disabling
To confirm that this was successful:
Input: Get-CASMailbox | Select *
Scroll through the list of mail clients and confirm that OneWinNativeOutlookEnabled has the required value next to it
To enable/disable access for your entire organization:
Run the PowerShell app as an administrator
Input: Connect-ExchangeOnline -UserPrincipalName
Input: Get-CASMailbox|Set-CASMailbox -OneWinNativeOutlookEnabled <$true> if enabling or if disabling

Change Category:
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Scope:
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Release Phase:

Created:
2022-05-07

updated:
2022-05-09