When sending and receiving emails from your Microsoft Outlook client, you may encounter the 0x800CCC90 error. This error can occur due to several reasons.

Some common contributing factors include multiple POP3 accounts in your outlook profile, port blocking, and issues with the Outlook client. If your email client is affected by this error, here are a few troubleshooting steps you can try to resolve the error in Windows.

1. Create and Configure a New Send and Receive Group

A common contributing factor to the 0x800CCC90 error is the existence of multiple POP3 accounts. To fix the error, you can create smaller Send and Receive Groups in the Outlook client. It is also useful if you deal with some accounts more often than others.

To create a new Send and Receive Group:

  1. Launch the Outlook client on your PC.
  2. Next, open the Send/Receive tab in the toolbar.
    outlook email client send receive groups
  3. Next, click the Send/Receive Groups drop-down and select Define Send/Receive Groups.
  4. In the Send/Receive Groups dialog, click the New button.
    new send receive groups outlook client windows
  5. Here, enter a name for the group and click OK.
  6. Next, select an account under the Accounts section.
  7. Now, check the Include the selected account in this group option.
    new send receive groups settings
  8. Under Account options, select the Send mail items and Receive mail items options.
  9. Next, select the Inbox option under the Folder Options section.
  10. Select the Download complete item including attachments option.
  11. Repeat the steps to configure more accounts and click OK and Close to save the changes.

2. Launch the App in Safe Mode

If the error persists, launch the Outlook client in Safe Mode. In Safe Mode, the app opens in its default state and helps you determine if a third-party add-in is causing the error. This works similarly to Windows Safe Mode but is limited to individual Microsoft apps.

To open the Outlook app in Safe Mode:

  1. Press the Win key and type "Outlook" to look for it on Windows Search. Don't select it rightaway when it appears.
  2. Next, press and hold the Ctrl key on your keyboard and double-click on the Outlook shortcut to launch the app. Don't release the Ctrl key until you see the Safe Mode prompt.
  3. Click Yes to confirm and start Outlook in Safe Mode.
    microsoft outlook safe mode
  4. Next, select a profile (Outlook) and click Yes.
    choose profile outlook safe mode
  5. When in Safe Mode, check if the error 0x800CCC90 exists when you send or receive the email.

If not, follow the steps below to identify and remove problematic plugins. To disable Outlook Add-ins:

  1. Launch the Outlook client.
  2. Click on File and then click on Options.
    outlook client windows file options
  3. In the Outlook Options dialog, open the Add-ins tab.
  4. At the bottom of the page, click on the Go button for Manage COM Add-ins.
    outlook options add_ins manage go
  5. In the Add-ins dialog, uncheck all the add-ins and click OK.
    outlook options add_ins manage go disable
  6. Next, restart the Outlook client, enable any add-in, and check if the error persists.
  7. Enable all the add-ins one by one until you find the troublesome plugin.

3. Remove and Re-Add Your Email Account

Another handy fix you can try is removing and re-adding your email account. This should work if the error is triggered due to a temporary issue.

To remove and re-add your email account in Outlook:

  1. Launch the Outlook client and click on File.
  2. In the right pane, click on the Account Settings drop-down and select Account Settings.
    outlook file account settings
  3. In the pop-up dialog, select the account you want to remove and click on Remove.
  4. Click Yes to confirm the action.
    outlook file account settings remove account
  5. To re-add the account, open Account Settings and click on New.
  6. Fill in your account details to log in.

4. Repair the Outlook Client

You can run the built-in repair tool to find and fix issues with the Outlook client. Since the Outlook app is part of Microsoft Office, you will need to run the repair tool for the entire Office suite to try and fix any issues with the app.

Make sure to save your open documents and close all the Microsoft Office apps if running before initiating the repair process.

To run the Outlook repair tool:

  1. Press Win + I to open Settings.
  2. Next, open the Apps tab in the left pane.
    Windows 11 settings apps and features
  3. Click on Apps & features and wait for the apps page to load.
  4. Here, locate your Microsoft Office version.
  5. Click the three-dots menu next to the app name and select Modify.
    Microsoft office 365 modify app
  6. In the repair dialog, select Online Repair. This option requires an active Internet connection and takes a little longer. If not, select Quick Repair.
    microsoft-office-repair-online
  7. Click the Repair button and then click Repair again to start the process.
  8. Once done, restart your PC and check if the error is resolved.

Fixing the 0x800CCC90 Outlook Error Code

This Outlook error can occur due to many reasons. But you should be able to resolve the error using the troubleshooting steps in the article. If the issue persists, check your third-party antivirus firewall settings. Disabling the firewall temporarily can help you identify any conflict between the apps.

If the error is resolved, but Outlook still doesn't receive emails, check your junk box, email sorting options, and block list to resolve the issue.