Outlook: New Outlook for Windows and web - Reading pane background image
To offer more personalization to end users, Outlook on the web and the new Outlook for Windows will now have the ability to display a background image in the reading pane whenever emails are not selected. This feature will be turned off by default for commercial customers. A user will be able to turn on a background image by going to Settings >> General>> Appearance from Outlook.
Expected Release Date:
March CY2023