How to Clear the New Outlook Cache Safely Without Losing Data

You may need to clear the cache in the new Outlook for Windows to fix performance problems or sync errors. The cache stores temporary data to make the app load faster, but it can sometimes become corrupted. This guide explains how to safely delete this temporary data without affecting your emails, calendar events, or account settings. You will learn the exact steps to clear the cache and what happens when you do.

What the New Outlook Cache Is and Why You Clear It

The new Outlook app, part of Microsoft 365, uses a local cache to store copies of your mailbox data. This includes email headers, calendar information, and contact pictures. The cache improves speed by letting you view items without waiting for a server download each time.

You clear this cache to resolve specific issues. A corrupted cache can cause emails not to appear, calendar events to show incorrectly, or the app to run slowly. Clearing it forces Outlook to rebuild this temporary data from your mail server. This process is safe because your actual emails and account configuration are stored online, not in the local cache folder.

What Gets Removed and What Stays Safe

Clearing the cache only removes locally stored temporary files. Your account credentials, email rules, and server-side folders remain untouched. Any emails you have permanently deleted from the server will also be gone, as the cache does not store independent copies. Your Outlook settings and preferences are also preserved.

Steps to Clear the Cache Using Outlook Settings

The safest method uses the built-in feature in the new Outlook app. This option is designed to clear temporary data without affecting your profile.

1. Open the new Outlook app
   Ensure you are using the new Outlook for Windows, not the classic desktop application. You can identify it by its simplified interface and the word “New” in the title bar.
2. Go to Settings
   Click the gear icon in the top-right corner of the app window to open the Settings pane.
3. Navigate to General > Storage
   In the Settings pane, select the “General” category from the left sidebar. Then, click on the “Storage” tab that appears on the right.
4. Clear the cache
   In the Storage section, you will see an option labeled “Clear local cache” or similar. Click the “Clear” button next to it. A confirmation dialog will appear.
5. Confirm the action
   Read the confirmation message, which explains that Outlook will restart. Click “Clear” or “OK” to proceed. The app will close and reopen automatically.
6. Wait for resynchronization
   After restarting, Outlook will begin downloading fresh data from your mail server. Your recent emails and calendar will repopulate. This may take a few minutes depending on your mailbox size and internet speed.

Manual Method to Clear the Cache via File Explorer

If the in-app option does not solve your problem, you can manually delete the cache folder. This method is more thorough.

1. Close Outlook completely
   Right-click the Outlook icon in the system tray and select “Quit” or use Task Manager to end the task. This ensures cache files are not locked.
2. Open the Run dialog
   Press the Windows key and the R key together on your keyboard. This opens the Run command box.
3. Enter the local app data path
   Type %localappdata% into the Run dialog box and press Enter. This command opens the Local AppData folder in File Explorer.
4. Locate and delete the cache folder
   In the opened folder, navigate to Packages > Microsoft.OutlookForWindows_8wekyb3d8bbwe > LocalCache. Select the entire “LocalCache” folder and delete it by pressing the Delete key or right-clicking and choosing Delete.
5. Restart Outlook
   Open the new Outlook app from the Start menu. The app will create a new, empty cache folder and begin syncing all data from your accounts.

Common Mistakes and Limitations to Avoid

Clearing Cache Does Not Fix All Sync Problems

If your emails are not syncing due to server issues or incorrect account settings, clearing the cache will not help. Check your internet connection and verify your account password in Settings > Accounts first. The cache clear only addresses problems caused by corrupted local data.

Not Closing Outlook Before Manual Deletion

If Outlook is running in the background, Windows will lock the cache files. Attempting to delete the LocalCache folder will result in an error stating the files are in use. Always confirm the app is closed via Task Manager before proceeding with the manual method.

Confusing Cache with Offline Outlook Data Files

The new Outlook cache is different from the classic Outlook Data File (.pst or .ost). Clearing the cache does not touch these larger data files. If you need to rebuild an offline data file for an Exchange or Microsoft 365 account, you must use the Account Settings menu to disable and re-enable Cached Exchange Mode, which is a separate process.

Cache Clearing Methods Compared

Item	In-App Clear Cache (Settings)	Manual Folder Deletion
Primary Use Case	Fixing minor glitches, slow performance, or missing recent items	Resolving persistent corruption issues when the in-app method fails
Complexity	Simple, guided steps within the Outlook interface	Advanced, requires navigating system folders
Data Impact	Clears most temporary data; some deep app state may remain	Removes all cached files for a complete reset
App Restart Required	Automatic restart initiated by Outlook	Manual restart required after closing the app yourself
Risk Level	Very low, protected by confirmation dialogs	Low, but user must ensure Outlook is fully closed

You can now safely clear the temporary cache in the new Outlook app to troubleshoot sync and performance issues. Start with the built-in tool under Settings > General > Storage for a quick fix. If problems continue, use the manual method by deleting the LocalCache folder. For ongoing performance concerns, regularly check for app updates in the Microsoft Store, as updates often include cache management improvements.