Microsoft has started rolling out a classic Outlook design for users of Outlook on the web and the new Outlook for Windows.
This new Outlook design will be rolled out as part of a targeted release starting in mid-August and is expected to be completed by the end of September. The theme will be generally available worldwide between the end of September and the end of October.
“When the setting is enabled, coordinated changes are applied across the entire Outlook experience, including visual style, layout, typography, icons, and select interactions.” Microsoft said in a Microsoft 365 Message Center update.
Once rolled out, the feature will not overwrite any existing admin configurations or automatically migrate users from classic Outlook to new Outlook.
Microsoft also added that the new interface style will be enabled by default for some users. However, you can disable it to switch to the default theme in Settings > General > Appearance.
“This update is intended to help users switching from classic Outlook by providing a more familiar user experience while retaining the features of the new Outlook,” it added.
“The setting is available to all users and can be enabled or disabled at any time. For most users, it is disabled by default. As part of a phased rollout, Microsoft will enable the setting by default for some users who are switching from classic Outlook to new Outlook. These users can change the setting at any time.”
The new Outlook (also known as Outlook for Windows), which still lacks some classic Outlook features, replaced Windows Mail as a pre-installed app on Windows 11 and Windows from October 2023 and January 2025, respectively.
Microsoft introduced this first preview version of the new Outlook client in May 2022. The app became generally available for personal accounts in September 2023 (about the September 26 Windows Fall Update and the Microsoft Store on Windows 11) and for commercial customers in August 2024.
Microsoft announced this in February postpone the new Outlook opt-out phase for enterprises from April 2026 to March 2027, giving enterprise administrators 12 additional months to prepare a phased migration to the new client.
Microsoft made this decision despite, according to the company, “experiencing strong and accelerating adoption of the new Outlook.”
In July, Microsoft also announced that it would deactivate Outlook Web Access (OWA) Light, a simplified version of the launched Outlook Web App email client about two decades ago as an alternative to OWA Premium in a future Exchange Server update.
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