How to Clear the Outlook Cache

Delete Microsoft Outlook's Cached Data

MS Outlook 2016 logo

 Microsoft

Microsoft Outlook stores files you've already used so that it can easily access them again should you need to. These files are known as cached files, and they can be safely deleted should you need to.

You might want to clear out the Outlook cache if old data still remains even after
you tried deleting it, something that often happens when removing and
reinstalling Outlook add-ins.

Another reason to delete Outlook's cached files is if autocomplete data or other
"behind-the-scenes" information is still popping up even after you've
deleted contacts or reinstalled Outlook.

Removing the cache in Outlook doesn't delete emails, contacts, or any other useful information. The cache is only there to help speed things up in some circumstances, so there's no need to think that it will delete any of your personal information.

  1. First, make sure Outlook is completely closed down. Save any work and then exit the program before continuing. Open the Run dialog box with the Windows Key + R shortcut. Then, copy and paste the following into the dialog box:

    %localappdata%\Microsoft\Outlook 

    Press Enter. A folder will open to Outlook's data folder, which is where cached files are stored.

    Screenshot of the cache folder in Outlook
  2. You'll see multiple files and folders listed here, but there's only one that you're after. You should see a folder called RoamCache. Double click this folder to open it and view all of the cache files.

    Screenshot of Outlook cache files
  3. Delete the cache files by holding the Shift key while selecting all of the files with your mouse. Press the Delete key on your keyboard to delete all of the files. Alternatively, you can right-click on the highlighted files and select Delete.

    Screenshot of deleting cache files in Outlook

    In some situations, it's smart to back up the file you're about to delete so that you can restore it should something go wrong. However, Outlook will automatically make new cache files after you delete them and open Outlook again.

  4. Now that the old cache files are gone, you can reopen Outlook so that it will start using a new cache files as you use Outlook features.

Clear Auto-Complete Cache

If you only want to clear the auto-complete cache, you can do it from inside Outlook. There are two options. You can either turn off auto-complete so the cached data doesn't display, or you can delete the auto-complete cache completely.

  1. Click on the “File” menu and choose “Options”.

    Screenshot of selecting Options in Outlook
  2. In the Outlook Options window, select the Mail tab. Scroll down to Send messages and uncheck Auto-Complete List to suggest names when typing in the To, Cc, and Bcc lines. Select OK to save the change.

    Screenshot of deselecting autocomplete in Outlook options
  3. If you want to clear out the auto-complete cache entirely, just select the Empty Auto-Complete List button. Select Yes on the confirmation pop-up to finish emptying the cache.

    Screenshot of clearing the Auto-Complete cache in Outlook
  4. Clearing the cache is a good way to remove the auto-complete history without completely disabling the auto-complete feature in Outlook.