Are you experiencing the error code 0x8004210B in Microsoft Outlook on Windows PC? If so, this post will help you. We will discuss this error in detail and how you can fix it.
What is 0x8004210B Sending error?
The Outlook error 0x8004210B is an error that occurs while sending or receiving an email. It indicates that the remote server that has stored your Outlook emails took too long to send or receive an email. When triggered, you get the following error message:
The operation timed out waiting for a response from the sending (SMPT) server. If you continue to receive this message, contact your server administrator or internet service provider (ISP).
Now, there can be different reasons behind the error code 0x8004210B in Outlook. It could be your weak or unstable internet connection causing the timeout error while sending an error. Besides that, incorrect email account settings can also be one of the reasons triggering this error code. It could be your corrupted email account or Outlook profile which is why you are experiencing this error code. An antivirus/firewall interference could also cause the same error.
Fix Outlook error 0x8004210B
If you receive Send/Receive error code 0x8004210B in Microsoft Outlook while sending or receiving an email, you can use the below methods to fix it:
- Check your network connection.
- Verify the SMTP settings.
- Repair or add a new email account.
- Repair your Outlook profile.
- Clear the stuck emails.
- Temporarily disable your antivirus/firewall.
1] Check your network connection
If you are facing some internet connectivity issue or your internet is not working fine, you will likely experience this error. So, make sure your internet is stable and active to use Outlook.
Outlook shows a Yellow triangle sign with Disconnected status below at the bottom of the window. So, check if there is any such text shown. If so, you can be sure that the error is triggered due to a weak or unstable internet connection. Hence, in that case, troubleshoot internet connectivity problems or try connecting to a different reliable network connection. You can also restart or reset your router to check if the issue is resolved.
Read: Connection to Microsoft Exchange is unavailable Outlook error.
2] Verify the SMTP settings
The error code 0x8004210B in Outlook could result from an incorrect email account and SMTP settings in the app. Hence, if the scenario is applicable, check your email account settings and make sure it is correctly configured. Here are the steps to do that:
First, open the Microsoft Outlook app and go to the File > Info option. Now, click on the Account Settings drop-down option and choose the Account Settings option.
In the appeared dialog window, select your account and click on the Change button. A new prompt will appear; tap on the More Settings button in it.
Next, navigate to the Outgoing Server tab and checkmark the My Outgoing server (SMTP) which requires authentication option, and make sure that a valid connection mode is configured.
After that, click on the Advanced tab and enter the correct port number inside the Outgoing server (SMTP) box; set it to 587.
Finally, press the OK button to save changes and then try sending emails to check if the error is gone. If not, we got more fixes that will help you resolve it. So, move on to the next fix.
See: There is a problem with the proxy server’s security certificate – Outlook.
3] Repair or add a new email account
An Outlook email account with corrupted files and settings can be one of the reasons triggering error code 0x8004210B in Outlook. Hence, if the scenario is applicable, you can either repair your email account or remove the current email account and add a new one to check if the error is gone.
To do that, first, open the Control Panel using the Windows Search feature. Now, press the Mail option. If you don’t see the option, type Mail in the search box and click on the Mail (Microsoft Outlook) option.
In the appeared Account Settings dialog window, click on the corrupted account and then press the Repair button. Then, click on the Next button and let it verify and repair your email account. When the process finishes, open Outlook and check if the error is resolved.
If repairing didn’t work, open the Account Settings then press the Remove button.
Once done removing the account, click on the Add button and then enter your email address, name, password, etc., to set up a new email account. When the account is added, select it and click on the Set as Default button.
You can now try sending emails in Outlook using the new account and see if the error code 0x8004210B is fixed.
See: Fix NEED PASSWORD error message in Microsoft Outlook.
4] Repair your Outlook profile
If your Outlook profile is corrupted, you will experience errors like 0x8004210B when trying to send emails. Hence, if the scenario is applicable, you can repair the corrupted Outlook profile in order to fix the error.
You can use the ScanPST.exe tool with Microsoft Outlook to repair a broken profile. Here’s how to use it.
First, press Win+E to open the File Explorer and then move to the location:
C:\Program Files\Microsoft Office\root\Office16
This the default locations where the ScanPST.exe file is present. It will differ based on the version of Microsoft Office you have installed.
Next, double-click on the ScanPST.exe file to run it. Now, press the Browse button and choose the input PST file, and click on the Start button to let it analyze the source file.
Then, checkmark the checkbox called Make backup of scanned file before repairing and press the Repair button to fix the PST file.
When done, restart the Outlook app and see if the error is fixed. In case you are unable to fix the Outlook profile, you can create a new Outlook profile and use it to check if the error is gone.
Read: How to fix Outlook Error 0X800408FC?
5] Clear the stuck emails
The error might be caused due to stuck emails in your Sent box. Hence, if the scenario applies to you, delete all such stuck emails where you are experiencing error code 0x8004210B and send fresh emails to check if the error is fixed or not. Here are the steps to do that:
First, open the Outlook app and go to the Send / Receive tab.
Now, press the Work Offline to disconnect the app from the internet.
Next, go to your Sent box and select the email message with which you are facing this error. Right-click on the email and choose the Delete option from the context menu to remove it. Similarly, you can delete other such emails.
Now, click on the Work Offline option again from the Send/Receive tab to connect to the internet.
Finally, you can try resending the emails in Outlook and see if the error 0x8004210B is fixed.
See: Outlook cannot connect to Gmail, keeps asking for password.
6] Temporarily disable your antivirus/firewall
Sometimes, the error is caused due to interference from your overprotective antivirus or firewall. So, in that case, you can disable your firewall or antivirus for some time and observe whether the error reoccurs. If not, you can be sure it was your security suite causing the error. If this is the scenario, you can add Outlook to the Exception or Exclusion list of your security program.
To allow Outlook through Windows Firewall, use the below steps:
- First, use the Windows key + I hotkey to open the Settings app.
- Now, navigate to the Privacy & security tab and click on the Windows Security > Firewall & network protection option.
- Next, press the Allow an app through firewall option.
- In the appeared window, press the Change settings button and checkmark the Microsoft Office Outlook checkbox.
- Once done, make sure both the Private and Public checkboxes present next to the Outlook app are ticked.
- Finally, click on the OK button to apply new changes and close the window. You can now open Outlook and check if the error code is fixed or not.
If the above fixes don’t help, try running Outlook in safe mode and see if the error is resolved. If the error is gone in safe mode, disable or remove suspicious add-ins that might be causing the error.
What is error code 80000000 in Outlook?
The error code 80000000 in Outlook says “Outlook is unable to connect to the proxy server autodiscover.” To fix this error code, you can check the compatibility of the Outlook client with the Exchange server version and make sure the Autodiscover service is running on your computer. Besides that, you can enable TLS 1.0 on the local Windows 11 machine, add TLS 1.2 to the Exchange server, or upgrade Exchange Server to resolve the error.
Now read: Fix 0x8004011c Outlook error when trying to set up email account.
