How to Fix Outlook Error 0x80070021 in Simple Steps

Summary:- MS Outlook is the most popular email client that allows users to store their information and is suggested by many industry professionals worldwide. It uses Outlook Data File(PST) to store entire mailbox data, and users can manage their emails, attachments, notes, journals, calendars, etc., efficiently. But sometimes, when any other program runs in the background or is improperly closed off the Outlook app, then there is a possibility that users may face an Outlook error 0x80070021.

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In this technical write-up, you will find the maximum possible solutions to fix Outlook error code 0x80070021. Before that, let us discuss something more about the error 0x80070021.

Outlook error 0x80070021 is one of the most common problems users face while entering wrong credentials or oversized PST file corruption. An error also occurs while using Outlook express, and even though it is not that complex, it still can make the Outlook account unreachable. When an error occurs, one can not access their email but can’t send it.

What are the Reasons Behind the Outlook Unexpected Error 0x80070021?

There are plenty of reasons behind the occurrence of Outlook indexing error 0x80070021. Some of the common errors are listed below:

Applications Running in the Background

The issue occurs due to several other applications running in the background that may use Outlook’s features for their process like Microsoft Office Communicator, Google Calendar Sync, Skype, etc.

Outlook Application ShutDown Directly

An issue occurs when one can shut down the Outlook application directly. Also, your Outlook may not close properly because of different obstacles like add-ins that are enabled is in the working stage.

Received Email is Corrupt or Infected

In Outlook 2016, 2013, 2010, etc., error code 0x80070021 occurs due to receiving corrupt or infected emails. It could come on any sent or received email items.

Configuration Setting in Outlook

If you are trying to add your Outlook account to another mail app, you might need the POP, IMAP, or SMTP settings for Outlook. But maybe a possibility that the issue occurs due to the wrong Configuration Setting.

Hardware problem

Hardware failure is also a reason behind the Outlook error, and due to this, users also may face the PST file corruption or damage issue. It can occur in the Data storage device, network device, and sudden power failure.

How to Fix Outlook Error 0x80070021 Manually?

Now, let’s check out different best methods to fix Outlook error 0x80070021. All the steps are easy to perform, and there are no chances of Outlook mailbox data loss.

1. Close Outlook App From Task Manager

You can use Task Manager on your system to close the working of the Outlook app and restart it again to fix the issue. Thus, follow the steps to-do-so:

  • Right-click on the Windows wizard and opt for Task Manager from the list.
  • You can also use the shortcut keys like Ctrl+Alt+Delete, on your keyboard.

  • Go to Outlook or any other program that uses Outlook features in the background processes.

  • Right-click on what you have selected and click on the End process.

2. Fix Outlook Error Code 0x80070021 Via System Restore

By restoring your system, you can troubleshoot the issue. Follow the steps to perform so, Start your PC as an administrator.

  • Open your desktop and select All Programs after choosing the “Start” button.
  • Then opt for the System Tools, an option from the drop-down list of Windows Accessories.
  • Now, move on to System Tools and go to System Restore.

  • Check the Show more restore points option and click the Next button to continue the process.
  • Select to restore your computer to a time earlier than when Outlook developed this error. Click Next>>Next.

  • A pop-up appears on your screen to confirm your decision, click the Finish button.

3. Remove Indexing Tool

To fix the Outlook Error 0x80070021, you will also have to Remove the Indexing Tool. So to remove that, implement the below procedure:

  • Open Outlook and then click the File tab.
  • Click on Options and then select the Add-ins.
  • Go to the Manage option and then tap on COM Add-ins.
  • Opt for Go which will display the list of all the installed Add-ins on your Outlook.
  • Finally, select Search email indexer and exclude it to fix the Outlook Error 0x80070021.
  • Now, close Outlook and restart it, then try to do the file back up again.

4. Just Try a clean boot to Fix Issue

Error 0x80070021: The process cannot access the file and also occur due to maximum usage of programs. Hence, you will have to try the clean boot to use Outlook with a minimum set of programs.

Step-By-Step Guide to Perform Clean Boot

  • Click the R and windows key simultaneously to open the Run tab.
  • Enter msconfig in the empty box and click on the Ok button to continue the process.
  • When a wizard pops up, go to the services tab and check the option that shows the Hide all Microsoft Services option. Here, select to disable all of them.

  • After that, go to the Startup option and tap on Open task manager.
  • You can see several startup options, and you can select the avoidable ones and then tap on the Disable button.

  • Start Outlook again to see if Outlook Error 0x80070021 gets fixed or not.

5. Uninstall the Installed Microsoft Office Communicator

If you have this installed Microsoft Office Communicator, then uninstalling it will help you to overcome the possibility of Outlook Error 0x80070021 or Outlook Error Code 0x800ccc0e occurrence.

Follow the steps to uninstall from your System

  • Open the Control Panel and then click on Program.
  • Under Programs, opt for the Uninstall a program option to continue.
  • Here, select the Microsoft office communicator and click the Uninstall button.
  • Once the process of deletion gets completed, start Outlook again.

One of these above methods will surely help you to fix the Outlook error 0x80070021 without losing integrity. However, if you still face any issue, then there is maybe a possibility that your PST file gets corrupted. Thus, to fix the corruption of the Outlook PST file, you may opt for the inbox repair tool(SCANPST.exe).

Steps to Fix Error 0x80070021 in Outlook Due to Corrupt PST

  1. First, exit Outlook and Open SCANPST.EXE on your system
  2. Click Browse to select the Outlook Data File (.pst) you want to scan.
  3. Choose the Start button to begin the scanning process.
  4. If the scan finds errors, click on the Repair button to start the process to fix them.
  5. When the repair of PST gets completed, start Outlook with the profile associated with the Outlook Data File(PST) you just fixed.

After fixing the corruption of the PST file, start Outlook and check whether the error 0x80070021 is solved. Moreover, if your Outlook PST file corruption can not get fixed manually, you can go through with a professional solution.

PST Data Recovery Tool is an effective and best software to restore MS Outlook PST file data. It is competent enough to recover corrupt PST data like Emails, Contacts, Calendars, Tasks, etc. Moreover, the software saves the recovered data into different file formats like PST, MBOX, MSG, DBX, EML, etc.

Microsoft Outlook PST Recovery Tool Working

Know How to Fix the Corruption of Microsoft Outlook Data File(PST) in steps

  1. Download and Run the Outlook PST Recovery Tool.
  2. Click on the Open button to browse the PST file from your system.
  3. Now, select the Recovery Mode as per the level of corruption.
  4. You can also view the details of the added PST file.
  5. Click the Ok button to start the scanning process.
  6. A tab pop-ups on your screen showing the scanning process gets completed.
  7. Select the folders from the preview panel and click on the Save button.
  8. Now, choose the saving path and format in which you want to save,i.e., PST.
  9. Opt for the inbuilt option from the software wizard and click on the Ok button.
  10. After the completion of the process, click Ok.


To conclude, this blog has introduced you to the top 5 best solutions to fix Outlook Error 0x80070021 in simple steps. These error pop-ups on your screen while you can manage your Outlook application. Thus, we understood the possible methods to troubleshoot the error successfully.

Moreover, If you are finding a better solution to fix the corruption of the PST file, you can use the best PST Data Recovery Tool. It supports all the versions of Outlook PST like 2019, 2016, 2013, 2010, etc.

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