How To Delete Outlook Cache? [Why Important!]

Most of the users, not even heard the word “Cache“, because it’s non of their business, all everybody knew is “OMG my Outlook is working slow” Why?

In this article, you will learn step by step process of “how to clear outlook cache“, Is it essential and what are the effects of ignoring removing it.

What is Cache?

Collection of temporary files/data, every electronic application, computer, or Laptop file creates a temporary file, which helps to easily retrieve data which in turn helps devices run faster. Those temporary files are also term as Cache.

What does clear cache mean & what it does?

Clearing cache removes all temporary files in specific computer application, saved cache files helps you speed up your operations, using Outlook auto-complete, it is essential to clear the cache when you notice a slowdown in the performance of the app, because at certain level cache cause issue for smooth working.

How to clear Outlook Cache? [Step by Step process]

Removing the Microsoft Outlook cache turn your application result quite efficient and also run smoothly. By clearing the data in the cache, you’re likely to improve Outlook’s performance, there is no doubt I personally remove cache in other applications which results instantly.

Here are a few steps tutorial~ 

Outlook Cache is like files that are already holding a folder in your computer system, you can navigate to the folder where they’re located and get rid of all of them at once.

  • Close Outlook in case it’s Open to processing clearing cache from the computer.
  • Press the Windows + R
  • Run Dialog Box pops up, Type %localappdata%\Microsoft\Outlookand Hit Ok.

How To Delete Outlook Cache

  • This step opens up the Outlook folder, which consists few files and folders >> Double-click the RoamCache folder (outlook cache location) to view the cache files.


  • The Folder consist of [DAT Files], Select all the files using (Ctrl + A) key, Then press the Delete key, or right-click the highlighted files and select Delete, all your temporary cache files removed from your Outlook.

How to Remove Auto-Complete Cache

Outlook autofill feature saves email address once you enter into “To”, “CC” & “BCC”, this feature is really a time saver and easy to use, the only issue with auto-complete is Cache, which later on slows down your system.

Disable Autocomplete features is the best option, then, is to clear the auto-complete cache. Disabling and remove autocomplete cache is a simple step process:

  • Lunch Microsoft Outlook >> Click on the File tab from the left-hand corner of the screen.
  • Click Options from the left sidebar of the screen.
  • Hit the Mail tab from the left-hand navigation section, and scroll down to the Send Messages section.

Remove Auto-Complete Cache

  • Uncheck Empty Auto-Complete List and also click Click the Empty Auto-Complete List button to get rid of everything all at once.

Click the Empty Auto-Complete List button

  • Click on Yes as final confirmation to clear Outlook auto-complete cache from your computer.

Clear Outlook Attachment Cache (Complete Guide)

Outlook emailing consist of tons of attachments, which use to commute regularly, opening attachment generates multiple caches/temporary files in Outlook, these type of cache files generated in a regular basis.

You can easily clear all attachment caches of Microsoft Outlook.

Follow the steps:

  • Press the Win + keys from your Keyboard >> Run dialog box popsup >> Enter “regedit” in the box
  • Click the Ok Button.

Clear Outlook Attachment Cache

  • A registry editor window opens, which consists of multiple folders.

registry editor

  • Click HKEY_CURRENT_USER >> Software >> Microsoft >> Office >> 16.0 >> Outlook >> Security, the complete address turn to be : Computer\HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Outlook\Security

You can also simply copy and paste the address into the address bar to get the results.

  • Open the Security folder >> Double click on OutlookSecureTempFolder to open it.

Attachment Cache

  • Edit String dialog box appears, copy the path in the Value data box using Ctrl+C, and then click the OK button.

String dialog box

  • Next is paste the value data you copied in the above step into any folder address bar of your computer and Hit Enter, You will get the results of temporary/ Cache files.

Temporary Cache files

  • Select all your temporary files using Ctrl + A keys, and delete using the delete key or delete option from the mouse right button.
  • Close all your opened files and folders and restart Microsoft Outlook with Cache free support.

Both the above method, help you get rid of unnecessary cache files which trouble you and slow down the work. Some of my friends ask me “What if you don’t clear cache in Outlook”, there is no harm in keeping all the cache files but in long run, those files exhaust system speed as well as space.

Although keeping all the cache files in your external hard drive before deleting is another professional manner in case things go wrong.

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