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Summary: Explore our comprehensive blog post on common Outlook errors: 0x8004210A, 0x800CCC0B, and 0x8004210B. We provide practical solutions to resolve these issues, including adjusting server timeout settings, addressing antivirus software interference, and verifying SMTP addresses. If the errors persist, our guide recommends using Kernel PST Repair software for efficient data recovery and a seamless Outlook experience.

Undoubtedly, you’ve encountered frustrating error messages while sending and receiving emails in MS Outlook. Codes like 0x8004210a, 0x800ccc0b, and 0x8004210b can become recurrent nuisances. Promptly resolving these errors becomes imperative to maintain a smooth email experience.

Have a Look at the Error Messages

Outlook Error 0x8004210a & Outlook Error 0x800ccc19

When you check your POP3 email account in Outlook, you may get error messages like:

  • “The operation timed out waiting for a response from the receiving (POP) server 0x8004210a.”
  • “A time-out occurred while communicating with the server 0x800ccc19”

To resolve error 0x8004210a, consider extending the server timeout period. Here are the steps to increase the server timeout period, applicable to Outlook 2010 and later versions:

  1. In Outlook, go to the Files menu, and click Info.
  2. Now click Account Settings, and again click Account Settings.
  3. Select the POP3 account, and click Change.
  4. Now click More Settings, and go to the Advanced tab.
  5. Now increase the server timeout setting and check if the issue is solved.

Another potential cause of this issue is anti-virus software interference. To prevent errors related to antivirus scanning configurations, consider disabling the ‘Scan incoming Email’ and ‘Scan outgoing Email’ options. Refer to your antivirus provider’s documentation or website for detailed steps. In the meantime, you can also explore general methods for resolving common Outlook errors, as mentioned in the latter part of this article.

Outlook Error 0x8004210b

The 0x8004210b error in Outlook typically occurs when there’s an issue with an SMTP address within a distribution list, such as incorrect or corrupted addresses. To resolve this error, it’s essential to meticulously inspect and verify all SMTP email addresses within the Outlook distribution list. Additionally, you can send test emails to each member of the distribution list to confirm the validity of their email addresses.

Some Common Outlook Errors and Their Solutions

Outlook often displays various errors, including 0x800ccc0b, during message send and receive operations. Here’s a brief overview of some of the most common Outlook errors:

  • No connection made (target machine refuses)
  • Server not found (Error 0x800ccc0d)
  • Connection to the server interrupted- (Sending/Receiving Error 0x800ccc0f)
  • Unexpected termination of server connection (due to server/network problems or inactivity for long time) – Error 0x800ccc0f
  • Outlook unable to connect to outgoing (SMTP) e-mail server – Error 0x80042109
  • Operation timeout – without response from receiving (POP) server – Error 0x8004210a
  • Timeout while communicating with the server – Error 0x800ccc19
  • Other prominent Outlook errors: 0x8007000c, 0x800C013b, and 0x8004210b
  • Miscellaneous Outlook errors: 0x80040119, 0x800ccc0e, 0x80042108, 0x800ccc79, 0x800ccc0b, 0x80040900, 0x800ccc81, 0x800ccc67, 0x80040600, and 0x800ccc15

Note: These issues are observed in Outlook 2016/2013/2010/2007/2003, and Outlook 2002/2000 (Standard Edition) versions.

Some General Methods to Deal With the Most Common Outlook Errors:

Many Outlook errors can be resolved by applying the general methods outlined here. It’s often necessary to try these methods sequentially, testing each one by sending a test message to confirm its effectiveness in eliminating the Outlook error.

  1. First verify internet connection and also ensure that mail server is not temporarily unavailable.
  2. Verify email account settings (the procedure may vary in different versions of Outlook).
  3. Delete any damaged or corrupted messages from your mailbox.
  4. Examine the antivirus software email scanning feature. This can be a reason for the error.
  5. Look for any discrepancy in the configuration of firewall software.
  6. Check your email account profile in MS Outlook. Preferably, create a new profile in Outlook. There will be no loss of emails, as by default both the Outlook Address Book and the personal folders PST files are automatically added to each new e-mail profile
  7. Start Outlook in a safe mode.
  8. Cleanup the Outlook Outbox (after performing Send/Receive operation) working in the offline mode.
  9. Check if all SMTP (Simple Mail Transfer Protocol) e-mail addresses in a distribution list are valid. Even one corrupted or wrongly formed SMTP address can give error 0x8004210b.
  10. Try repairing Outlook. If you are good technically, you can try the Microsoft tools first. Otherwise, you can try user-friendly third party tools like Kernel for Outlook PST Repair.


We’ve provided a range of useful methods to resolve the aforementioned errors. However, if these methods prove ineffective, consider using Kernel Outlook PST Repair software to scan and recover your PST file. After scanning, our software will display a preview of the recovered items. Once you save the data into a new PST file, you can seamlessly import it into Outlook, ensuring error-free functionality.

Kernel for Outlook PST Repair