When this will happen:
We will begin rolling out in early October 2023 and expect to complete rollout by late October 2023.
How this will affect your organization:
When viewing folders in the Outlook Mobile sidebar users will now see a “>” button that expands or collapses the current row, revealing any subfolders it may contain.
What you need to do to prepare:
The feature will automatically be enabled and will only appear for users who have a nested folder structure in Mail. For those who don’t use subfolders there is no change in functionality.