Many organizations rely on MS Outlook for email communication. While using Outlook is generally straightforward, users often encounter errors that can make it challenging. One such error is '0x800CCC67,' which is a common issue for Outlook users.

In this article, we will explore the causes of the '0x800CCC67' error in MS Outlook and discuss various solutions to resolve this issue.

Reasons behind Outlook 0x800CCC67 error

The '0x800CCC67' error in Outlook can occur due to various reasons, and there is no single fixed cause. Some common causes of this error include:

  • Incomplete download or installing Outlook for the first time on a new system
  • Removal of Outlook related files by some third-party applications
  • Due to malware or virus infection
  • If the registry files get corrupted due to MS Outlook installation
Messages you get with 0x800CCC67 error

When MS Outlook if suffering from 0x800CCC67, you will receive the following error messages on your screen.

  • Error 0x800CCC67 appears on the screen, and MS Outlook crashes immediately
  • "SMTP_421_NOT_AVAILABLE" message appears on the screen
  • The computer starts freezing repeatedly
  • Windows becomes slow and provides a late response to any input

If you are facing any of these messages or scenarios, then the MS Outlook is facing the 0x800CCC67 error. So, let's move to the solutions to fix this error.

Methods to Fix Outlook 0x800CCC67 Error

There are various methods you can try to fix the '0x800CCC67' error in Outlook. Here are some reliable solutions to resolve this error:

Registry File Repair

One method to resolve the error is by repairing or editing the Windows registry files. However, it's essential to have a good understanding of editing registry files, as incorrect changes can lead to further issues. Here's how you can do it:

Disable the antivirus

Another approach to resolve this error is to reinstall Microsoft Outlook on your system. The process for reinstalling Outlook may vary depending on the version of Outlook you're using and the operating system you have. Here, we'll provide instructions for reinstalling Outlook on Windows 10.

Reinstall MS Outlook on your System

Another method that can be utilized to fix the error is reinstalling MS Outlook on the system. Now, whether you're using Outlook 2007 or 2016, the installation process depends on the operating system. Here, we will tell you how to reinstall Outlook on Windows 10.

  1. Go to the Start menu and search for MS Outlook.
  2. Right-click on the MS Outlook icon to check the available options.
  3. Click Uninstall to remove Outlook from your windows.

After uninstalling MS Outlook, you can easily reinstall it from the downloaded file.

Change the SMTP port

When dealing with email applications, there are various ports used, and SMTP (Simple Mail Transfer Protocol) is one of the crucial ones. To resolve the error, you should verify that the SMTP port is configured correctly. To do this, access your email settings and review the specified port under the outgoing mail server settings.

If you've adjusted the ports and the issue persists, you can attempt to resolve it by powering off your router for a full minute and then turning it back on to refresh the connection.

Scan the system for virus or malware

Sometimes, viruses or malware can disrupt Outlook's functionality and trigger this error. It's highly recommended to scan your system for any virus or malware activity. You can use Microsoft's built-in Windows Defender Firewall to remove any viruses from your system. If you don't have antivirus software, consider installing one and perform a system scan to check for any viruses.

Restore the system

Restoring your system allows you to revert your computer's settings to a previous state, including the settings for installed applications. To restore your system in Windows 10, you should have previously enabled the System Restore feature. This feature allows you to return your system's settings and configurations to a previous state, effectively undoing changes made after that restore point was created.

Use a professional Outlook Repair tool

If none of the previously mentioned methods resolve the 0x800CCC67 error, it's possible that the PST file associated with Outlook is corrupted and causing the issue. In such cases, it is highly recommended to repair the PST file. Repairing PST files can be a bit tricky, and manual methods may not always be effective. Therefore, it's advisable to use a specialized tool like the Kernel for Outlook PST Repair tool. This software is designed to efficiently repair and recover data from corrupted or damaged Outlook PST files of any size.


"Outlook is a widely used email client that helps users manage their email, calendar, and contacts. While it's a powerful tool, it's not immune to errors and issues. One common error that Outlook users may encounter is the 0x800CCC67 error. This error can be caused by various factors, including incorrect settings, antivirus interference, or even a corrupted PST file. In this article, we've explored the possible causes of this error and provided solutions to help users resolve it. Whether it's editing registry settings, disabling third-party antivirus, or repairing the PST file, there are steps you can take to troubleshoot and fix the 0x800CCC67 error in Outlook.