Error 421 is a common SMTP (Simple Mail Transfer Protocol) Outlook error message. MS Outlook is one of the best and popular email applications widely used by PC Windows users for sending and receiving emails within and outside workplaces.
It is most commonly used in offices by professionals for faster communication.
This error may occur while sending and receiving emails on the server. The error 421 messages is displayed in either of the following formats:
“An unknown error has occurred: Server error 421”
"Could not send your message. Error 421"
421 4.2.1 : (DYN:T1) http://postmaster.info.aol.com/errors/421dynt1.html
421 4.3.1 Out of disk space for temp file
421 4.3.2 All server ports are busy
421 Downstream server error
421 Fork failed
421 Greylisting enabled, please try later
“An unknown error has occurred. Subject ‘Testing’, Account: ‘pop.charter.net’, Server: ‘mail.charter.net’, Protocol: SMTP, Server Response:
’421 Message rejected’, Port: 25, Secure(SSL): No, Server Error: 421, Error Number: 0x800CCC67”
Error CausesSome common causes for this critical Outlook error are:
This is a critical Outlook error that should be resolved timely. If you delay, it may cause you a great deal of inconvenience.
The error code 421 hampers your ability to access your email account, send and receive emails, add new contacts, view emails, calendar entries, and journals. In other words, it just brings your email activities to a standstill locking you out of the account.
To resolve this error code on your system, you don’t always have to hire a professional or call the network personnel to do the job. It may be a critical error but the good news is that it is quite easy to fix. Even if you don’t have technical expertise, you can still repair it.
Here are some of the best methods to repair this issue on your system:
Try changing your server settings. Here set the inbound connections limit at the maximum limit.
After the process is complete, try accessing your Outlook email account again; if it works, then that’s great the error 421 is resolved. However, if it doesn’t, then the problem could be related to viral infection.
If the cause of the error is PST files corruption, then not only will you be locked out of your email account, you are also at risk of losing all the data stored in your email account.
However, the best way to resolve the error and ensure full data recovery is to download a reliable PST repair tool. By running a PST repair tool on your system, you can resolve the error 421 right away. It recovers your data, repairs corrupt and damaged PST files.
If viral infection and Trojans are causing the error 421 to pop up on your system, then it is recommended to download and scan your PC with Restoro.
This is an advanced, intuitive, and user-friendly PC fixer. It is not just an antivirus but also a system optimizer and a registry cleaner.
Unlike common antivirus software that only removes viruses and simultaneously slows down the system’s speed, Restoro removes all types of malicious software on your PC including malware, spyware, Trojans, and viruses, and also boosts the speed of your PC significantly.
It is safe, easy to operate, and a quick fixer. It is compatible with all Windows versions.
Click here to download Restoro and resolve error 421 today!

“The boot configuration data store could not be opened”while you try to carry out any command on the bcedit.exe, then you’ve come to the right place as this post will guide you on how you can fix this error in Windows 10. This kind of error could pop up if the system is not able to locate the specified file. It is also possible that the requested system device can’t be found or that the boot configuration data store could not be opened. In addition, when you open the System Configuration or MSConfig, you might notice that there is no Boot data, and according to the reports, is that when you try to dual boot the computer, the installer will replace the default bootloader.
“There were some problems installing updates, but we’ll try again later. If you keep seeing this and want to search the web or contact support for information this may help: (0x8024002e)”.Common symptoms include:
Error Causes“Windows Resource Protection did not find any integrity violations.” This means you do not have any missing or damaged system files.OR you may receive a message saying:
“Windows Resource Protection could not perform the requested operation.”To resolve this problem, run the System File Checker in safe mode and make sure that the PendingDeletes and PendingRenames folders exist under %WinDir%WinSxSTemp.
OR you may also receive a message saying, “Windows Resource Protection found corrupt files and successfully repaired them. Details are included in the CBS.Log%WinDir%LogsCBSCBS.log.” OR you may receive a message saying, “Windows Resource Protection found corrupt files but was unable to fix some of them. Details are included in the CBS.Log%WinDir%LogsCBSCBS.log.”
In the last article, we have covered various advantages of Apple hardware over Windows PC, however, PC has their own strengths and advantages over MACs as well. Join us as we explore why would you choose Windows PC over MAC.

If you like to customize and build your own hardware and customize your existing computer then MACs are out of the picture, on other hand, computers based on Windows operating system are much more flexible in terms of customization.
While Apple hardware is locked and only allows small changes to it, computers running on Windows are free and open to various upgrades and modifications so if you like to play with hardware Windows is your platform.
There are games on MAC true but their numbers can not compare to games available for the Windows platform. On top of that, most latest and best gaming hardware is not even available on Apple platforms so if you plan to game in high resolutions and play the latest games there really is no option other than Windows.
Windows Platforms also has multiple emulators that you can use to play games from other older platforms and Microsoft since it owns Xbox has some great plans for both PC and Xbox gaming.
Since the introduction of the new MAC OS X, apple really lost a lot of application back compatibility, and a lot of old legacy software can not be run on modern Apple computers. Windows on the other hand have always tried and succeeded in keeping maximum compatibility with older and legacy software.
Also on the Windows platform, there is a lot of community support for old and legacy software so even if it is not officially supported it is backed up by the community.
In terms of where can you find the most different software, you need to look no further than the Windows platform. How Windows itself has great backward compatibility and a lot of developers are using it to create new software thanks to Visual Studio and .NET Windows has cemented itself as a platform with the most available software.
The popularity of Windows as the home operating system and as a gaming platform has made it quite interesting in eyes of various developers and tons of small applications are made daily for it. Windows 11 has also brought native android support to it and that has just expanded its already impressive catalog of applications.
Overall Windows PC is most appealing for users that like to be able to choose everything, from hardware components to software they would like to use. No other platform will give you larger freedom of choice and better personalization options.
Windows 7 features Troubleshooting Wizard, an automated tool that helps users resolve several PC-related problems such as accessing shared files or internet connectivity to name a few.‘An unexpected error has occurred’- The troubleshooting wizard can’t continue
Error code: 0x80131700'
Did you previously use Windows 7 or 8 but decided to run with the latest Windows 0S, Windows 10? An early error message encountered was activation error code 0Xc004F074. Error code 0Xc004F074 is manifested when the user fails to activate Windows directly after the installation of Windows 10. This occurs if the previous operating system on your computer was Key Management Service (KMS) activated.
The KMT provides a more seamless operation when users are activating volume license editions of Microsoft Windows and Office. This process tends to be clear to end-users of the system.
Symptoms of error code 0Xc004F074 include:
Error CausesVarious factors might incite error code 0Xc004F074. A primary cause is a discrepancy or difference between the KMS client and the KMS host machine. The host computer could possibly be operating a Windows Server 2003 or Windows Server 2008, while the client runs on OS Windows 7 or Windows Server 2008 R2. To supplement, the computer’s time might be a contributing factor. The time on the host machine and client might show a difference (Usually the host time exceeds 4 hours).
Are you running later versions of Windows Server? Use an update that fixes or installs KMS on your computer. The update is available on Microsoft’s website. Keep clearly in mind that the update is only for Windows Server 2013 Service Pack 1 and later versions of Windows Server 2003.
This step is similar to the aforementioned. However, it applies to Windows Vista and Windows Server 2008. This ensures the service is extended to Windows 7 and Windows Server 2008 R2.
It was previously mentioned that the time reflected on the KMS host and client might cause error code 0Xc004F074 to manifest. A simple fix to adhere to is to always ensure that the time between both is updated. To Resync the time on the client, execute the following command.
w32tm /resync
For this method to be successfully deployed, you’ll need to have in your possession an activation key or KMSpico Key. As you cannot apply the new key with the existing one, remove or uninstall the initial key. To perform this step, open the command prompt. This should be done while the computer is in admin mode. Then, run the command
(slmgr.vbs /dlv)
It should be executed without the brackets and before you have removed the existing key.
After executing the command, you’ll encounter the description:
Windows(R) Operating System, VOLUME_KMS_WS12_R2 channel
Move along with the process by applying the slmgr.vbs /upk to uninstall the existing KMS key.
After the old key is uninstalled, you’re ready to apply the following:
slmgr.vbs /ipk <NewKMSProductKey>
To check if things are in place and complete the process, follow the steps below: PC Settings >Update and Security > Activation
Error CausesWhen you receive the error 0x800ccc79 it may hamper your ability to send emails. Therefore it is advisable to fix it to ensure your emails are sent and received without any difficulty.
This Outlook error 0x800ccc79 is quite easy to repair. By following the quick fix 0x800ccc79 error code solutions given below you can resolve this error in just a couple of minutes.
Here’s what you need to do to fix this error right away:
Solution: If the error occurs due to Outlook Express being configured to use the SSL protocol while sending and receiving emails via the web, then to resolve it, you need to allow Outlook Express to bypass the Secure Socket Layer settings.
To do so, click on ‘tools’ and then on ‘Accounts’. Now select the email account that you want to modify.
Now select the ‘Properties’ tab and then click on ‘Advanced Settings’.
Here search for the following text message ‘This server requires a secure connection’. Once you locate it, uncheck all the checkboxes given next to this option. After that save the changes and restart Outlook Express to see bring the changes into effect.
Solution: If the error 0x800ccc79 occurs due to missing or corrupt registry entries, then the best way to fix this error is to download and install a good registry cleaner on your PC.
The registry cleaner will help you clean your corrupt and damaged Windows registry entries and get rid of this error right away. It is suggested you download the registry cleaner tool from a reliable website to avoid any malware or virus downloads simultaneously.
Once you download the registry cleaner on your system, click on scan. The cleaner will scan your computer completely for registry errors and show you the results in a list form.
After the scanning is complete, click on repair to fix the errors.
So, next time, if you or anyone at your office comes across the Outlook Express error 0x800ccc79, you can try these solutions and fix the error immediately without waiting for the network personnel to come and resolve it.