How to Fix Microsoft Outlook 0x800CCC05 Error

Updated June 2024: Stop error messages and fix your computer problem with this tool. Get it now at this link
  1. Download and install the software.
  2. It will scan your computer for problems.
  3. The tool will then fix the issues that were found.

Microsoft Outlook is a wonderful application that is not only used as an email client, but can also be used as an efficient tool for managing data such as: B. to store contacts, schedule appointments, manage notes, RSS feeds, newspapers, etc. All data related to Outlook is stored in a reliable file called PST, which changes every time you open MS Outlook or add something.

However, in various cases, your Outlook PST file may get corrupted and thus prevent access to all your items from MS Outlook. In such cases, you will see various error messages. 0x800ccc05 is one of the common Outlook error messages. This error message can be caused by two main reasons. One is the server is down and the other is due to corrupted PST files. You can fix the first problem by checking your internet connection.

Causes of error 0x800CCC05

Users face an error where Outlook cannot establish a secure connection to the mail server. The root cause of the error is a network firewall that breaks the connection between Outlook and the mail server.

How to fix an Outlook 0x800CCC05 error that cannot connect to the server:

Disable Windows Firewall

Another thing MS Outlook can block is Windows Firewall. Therefore, disabling the firewall is another possible solution to Outlook error 0x800CCC05. Here’s how to configure Windows Firewall settings in Windows 10.

  • Press the Cortana button on the taskbar to open this app.
  • Enter the keyword “Windows Firewall” in the Cortana search box, and then select to open Windows Defender Firewall.
  • Click Turn Windows Firewall on or off to open the options.
  • From there, select both options to disable Windows Defender Firewall and click OK.
  • You can also check if Outlook is allowed through Windows Firewall by clicking Allow an application or feature through Windows Defender Firewall.
  • Click the Change Settings button and scroll to Outlook in the list of allowed applications.
  • Check both Outlook boxes if they are not checked.
  • Then press the OK button to confirm the new setting.

After completing the above steps, it is recommended to check if the problem has been resolved. If the error persists, you should activate the firewall immediately to protect Outlook from virus or spyware attacks.

Run Outlook in safe mode.

Assuming that all of the above methods can correct this error, it is very likely that one of the existing superstructures is criminal. Therefore, you should learn about this reason.

Updated: June 2024

We highly recommend that you use this tool for your error. Furthermore, this tool detects and removes common computer errors, protects you from loss of files, malware, and hardware failures, and optimizes your device for maximum performance. This software will help you fix your PC problems and prevent others from happening again:

  • Step 1 : Install PC Repair & Optimizer Tool (Windows 10, 8, 7, XP, Vista).
  • Step 2 : Click Start Scan to find out what issues are causing PC problems.
  • Step 3 : Click on Repair All to correct all issues.


  • Close Outlook and go to the Start menu. In the search box, type Outlook.exe / safe and press Enter to start Outlook in safe mode. Start Outlook in safe mode
  • Then go to File> Options> Settings> Go.
  • In the next dialog box, delete one add-on at a time and restart Outlook as normal to check if the add-on is affected. Delete Outlook add-ons

Disable Anti Virus Programs

Programs such as Antivirus (Norton and Mcafee) and Firewall provide a high level of security to protect our computer and other objects from virus and malware attacks. In most cases, antivirus programs make it difficult to send and receive emails in MS Outlook (as Norton found this more annoying for Outlook 2010).

Set the level of protection for your firewall settings as supported for this factor (so that the firewall can allow these files to access the Internet).


All methods are safe to use given the severity of the problem. Hope these methods help you fix Outlook error 0x800CCC05. Sometimes these problems are also caused by errors in the Internet and Exchange Server connections. So keep these simple things in mind before taking any serious action.

RECOMMENATION: Click here for help with Windows errors.