Microsoft is adding a visual theme to New Outlook and Outlook on the Web that mimics the look and layout of Classic Outlook, but the cosmetic update does nothing to restore missing features such as offline support and COM add-in compatibility. The move comes as Microsoft pushes users off Classic Outlook, which is scheduled for eventual removal.

What You Need to Know

This update applies to both New Outlook for Windows and Outlook on the Web. It adds a coordinated style change but does not bring back features removed from Classic Outlook. Users who rely on offline functionality or custom COM add-ins will still lack those capabilities. The migration away from Classic Outlook is happening in phases, with full opt-out windows extending into 2027 and support continuing until at least 2029.

A Familiar Face Without the Functionality

The new setting, which Microsoft says applies coordinated changes across visual styling, layout, typography, icons and selected interactions, is intended to ease the transition for users moving from Classic Outlook. When enabled, New Outlook and Outlook on the Web adopt a more traditional appearance. However, the change is purely cosmetic. Microsoft has confirmed that it will not add back the bits from Classic Outlook that are currently missing from New Outlook.

  • Offline support: New Outlook still has limited offline capabilities compared to Classic Outlook.
  • COM add-in framework: Microsoft has confirmed that COM add-ins will never appear in New Outlook, impacting enterprise workflows.
  • Outlook Data Files: Importing calendars and contacts from .pst files is partially supported but full support remains in the future.

Why This Matters

Organizations that depend on Classic Outlook's offline mode or custom add-ins face a significant operational gap when migrating to New Outlook. The cosmetic theme may satisfy some users but hides deeper compatibility issues. IT administrators must plan for the eventual loss of Classic Outlook, even though support continues until at least 2029. For enterprise customers, the change represents a shift away from a highly extensible email client toward a more standardized platform that prioritizes cloud connectivity.

Microsoft is currently in the opt-in phase for New Outlook. Users can try the new client and switch back to Classic Outlook. In 2027, the opt-out phase begins, requiring users to actively choose to stay on Classic Outlook. Eventually, Microsoft will reach a cutover stage where returning to Classic Outlook becomes impossible. The company has promised at least 12 months' notice for administrators. The targeted release of the visual theme toggle is expected to be complete by the end of September, with worldwide rollout happening between late September and the end of October.

For now, users can make New Outlook and Outlook on the Web look a bit like the doomed Classic Outlook. The setting is accessible in appearance settings. Microsoft says the update is designed to help users transitioning from classic Outlook by providing a more familiar experience while maintaining the capabilities of the new Outlook.