Using classic Outlook for Windows in business environments
Classic Outlook is not shutting down on April 1, 2027 based on the provided Microsoft content.
What is supported by the available information:
- Microsoft is gradually transitioning from classic Outlook to new Outlook for Windows.
- New Outlook has been generally available since August 2024.
- During the current phase, classic Outlook remains available and users can switch to new Outlook with the Try the new Outlook toggle.
- In new Outlook, users can still choose to open classic Outlook or switch back to classic Outlook.
- For small and medium businesses on Current Channel with a Business plan, automatic switching begins starting January 2025 after in-app notifications, and users can switch back to classic Outlook at any time using the toggle in new Outlook.
- Both users and IT admins can turn off the automatic switch if not ready.
- Microsoft recommends running classic Outlook and new Outlook side-by-side during preview and adoption to maintain productivity.
- The feature comparison page confirms that new Outlook does not yet match classic Outlook feature-for-feature; some items are marked Available, Partially available, Not supported, Under investigation, or Upcoming.
If the goal is to stay on classic Outlook as long as possible, the supported actions in the provided content are:
- In classic Outlook, go to File > Options > General > New Outlook options.
- Uncheck Automatically switch me to new Outlook if that option is shown.
- If already in new Outlook, use the toggle to switch back to classic Outlook.
- For business environments, IT admins can opt out of the automatic migration experience.
- Consider using classic Outlook and new Outlook side-by-side while validating whether required workflows are available in new Outlook.
For executive assistant and other power-user workflows, the most relevant Microsoft-supported path in the provided content is to compare needed features against the feature matrix and use Help > Give Feedback in new Outlook for gaps.