How To Revert To Legacy Outlook – Legacy Outlook Version Reversion

by

Returning to legacy Outlook means disabling the new interface through the application’s experimental features toggle. If you are wondering how to revert to legacy outlook, you are not alone—many users find the new Outlook interface confusing or slow. This guide walks you through the exact steps to switch back, whether you use the desktop app, web version, or Microsoft 365.

Understanding The Need To Revert

The new Outlook for Windows rolled out in 2023, replacing the classic version for many users. While it offers modern features, it lacks some tools like offline access, custom views, and integration with third-party add-ins. If you prefer the old interface, reverting is straightforward.

Microsoft provides a toggle in the settings to switch between the new and legacy versions. However, this option may be hidden or greyed out depending on your account type. Below, we cover every method to restore the classic Outlook experience.

Why Users Want To Go Back

Common reasons include missing features, slower performance, or a cluttered layout. The legacy version is more stable for power users who rely on advanced rules, shared mailboxes, or PST files. Additionally, the new Outlook forces online-only access, which can be a problem with slow internet.

How To Revert To Legacy Outlook

Follow these steps to disable the new interface and return to the classic Outlook. The process varies slightly depending on your version.

Method 1: Using The Toggle In Outlook Desktop

This is the simplest method for most users. The toggle is located in the top-right corner of the window.

  1. Open Outlook on your Windows PC.
  2. Look for a toggle switch labeled “Try the new Outlook” at the top of the window. If it is turned on, click it to turn it off.
  3. If you see “New Outlook” instead, click it and select “Turn off” from the dropdown menu.
  4. Restart Outlook to apply the changes.

If the toggle is missing, your organization may have disabled it. In that case, use the registry method below.

Method 2: Through Outlook Settings

Some versions hide the toggle inside the settings menu. Here is how to find it:

  1. Open Outlook and go to File > Options.
  2. Select General from the left pane.
  3. Under “Outlook preferences,” look for “Enable the new Outlook.” Uncheck this box.
  4. Click OK and restart Outlook.

This method works for Outlook 2019, 2021, and Microsoft 365 versions. If the option is greyed out, proceed to the next method.

Method 3: Registry Edit For Advanced Users

Editing the Windows Registry forces Outlook to use the legacy version. Be careful—incorrect changes can break your system. Back up your registry first.

  1. Press Win + R, type regedit, and press Enter.
  2. Navigate to: HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Options\General
  3. Right-click on the right pane and select New > DWORD (32-bit) Value.
  4. Name it DisableNewOutlook.
  5. Double-click it and set the value to 1.
  6. Close the Registry Editor and restart Outlook.

After this, Outlook will load the classic interface. To revert back, change the value to 0 or delete the key.

Method 4: Group Policy For IT Admins

If you manage multiple computers, use Group Policy to disable the new Outlook for all users.

  1. Open the Group Policy Management Console.
  2. Create a new policy or edit an existing one.
  3. Navigate to: User Configuration > Administrative Templates > Microsoft Outlook 2016 > Outlook Options > Other
  4. Enable the setting “Do not allow the new Outlook to be used.”
  5. Apply the policy and update the clients using gpupdate /force.

This method ensures users cannot switch to the new version accidentally.

Reverting In Outlook For Web

The web version also has a new interface. To revert, follow these steps:

  1. Open Outlook on the web (outlook.com or your work portal).
  2. Click the gear icon in the top-right corner to open settings.
  3. Search for “Try the new Outlook” in the settings search bar.
  4. Toggle it off. The page will reload in the classic view.

If the option is missing, your admin may have enforced the new design. Contact your IT department for help.

What If The Toggle Is Missing?

Sometimes the toggle disappears after an update. Here are workarounds:

  • Check for updates: Go to File > Office Account > Update Options > Update Now. After updating, the toggle may reappear.
  • Use the registry method above—it bypasses the toggle entirely.
  • Reinstall Outlook: Uninstall and reinstall the Office suite. Choose the “Classic” version during setup if prompted.

Common Issues After Reverting

After switching back, you might notice some changes. Here is what to expect:

  • Your email accounts will remain intact.
  • Custom rules and signatures should work as before.
  • Add-ins that were disabled in the new Outlook will re-enable.
  • You may lose some modern features like integrated calendar from Google or iCloud.

If you encounter errors, restart Outlook or repair your Office installation via Control Panel.

How To Stay On Legacy Outlook Permanently

Microsoft plans to phase out the legacy version eventually. To delay the switch:

  • Disable automatic updates for Office. Go to File > Office Account > Update Options > Disable Updates.
  • Use the registry key mentioned earlier—it prevents the new Outlook from loading even after updates.
  • Switch to Outlook 2019 or 2021, which are not forced to upgrade.

Note that disabling updates means you miss security patches. Weigh the risks carefully.

Frequently Asked Questions

Can I revert to legacy Outlook on Mac?

Yes, but the process is different. On Mac, open Outlook, go to Outlook > Preferences > General, and uncheck “Enable the new Outlook.” Restart the app.

Will I lose my emails after reverting?

No, your emails, contacts, and calendar events remain safe. Reverting only changes the interface, not your data.

How do I revert to legacy Outlook if the toggle is greyed out?

Use the registry method (Method 3) or ask your IT admin to disable the new Outlook via Group Policy.

Does reverting affect shared mailboxes?

No, shared mailboxes work the same in both versions. However, the legacy version may load them faster.

Can I switch back to the new Outlook later?

Yes, simply re-enable the toggle or set the registry value to 0. The new Outlook will be available again.

Final Thoughts On Reverting

Knowing how to revert to legacy outlook gives you control over your email experience. Whether you use the toggle, registry edit, or group policy, the steps are simple. Most users can switch back in under five minutes.

If you still face issues, check Microsoft’s support forums or contact your IT department. The legacy Outlook remains a reliable tool for many, and with these methods, you can keep using it as long as you need.

Remember to back up your settings before making changes, especially if you edit the registry. With the right approach, you can enjoy the classic Outlook without interruptions.