Microsoft Brings Back Classic Outlook Theme for New Outlook Users

Microsoft has started rolling out a Classic Outlook theme for users of the New Outlook on Windows and Outlook on the web. The new theme is being introduced as part of a targeted release, which began in mid-August and is expected to complete by the end of September. Once rolled out, the feature will not override any existing administrator configurations or automatically migrate users from Classic Outlook to the New Outlook.

According to Microsoft, the Classic Outlook theme toggle will be available to all users and can be turned on or off at any time. It will be off by default for most users, but enabled by default for some users moving from Classic Outlook to the New Outlook. Those users can change the setting at any time.

The New Outlook has been gaining traction since its introduction in May 2022 as a preview version. It replaced Windows Mail as a pre-installed app on Windows 11 and Windows starting in October 2023 and January 2025, respectively. Microsoft has seen strong adoption of the new client, with users transitioning from Classic Outlook.