Fix Sending reported error 0x8004210B in Microsoft Outlook

Microsoft Outlook lets you to access the old emails without the Internet connection. When the Internet connection is active, you can download all the emails and also perform the send and receive. Sometimes, if the email configuration settings are incorrect, or for any other reason, you may encounter the issue with sending reported error 0x8004210B in Microsoft Outlook.

The error message appears as below.

Task – Sending ‘reported error 0x8004210B. The operation timed out waiting for a response from the sending (SMTP) server. If you continue to receive this message, contact your server administrator or Internet Service Provider (ISP).

This issue usually occurs when either your ISP or firewall in your local machine blocks SMTP port 25 or 587. You may check it by simply telnet on port 25 on your domain.

If you are facing this Outlook issue on your computer, this guide helps you to fix it by providing the relevant troubleshooting steps.

How to fix sending reported error 0x8004210B in Microsoft Outlook?

Follow the below resolution steps one by one and check if the issue gets fix after each troubleshooting step. If the issue remains, you can proceed with the further resolution steps.

Quick Note: Before proceeding with the resolution steps, we suggest you to create a System Restore point first. If something goes wrong during the troubleshooting, you can restore your computer back to previous working state.

Check your Internet connection:

Before proceeding with any further steps, we just want you to make sure that you have active Internet connection. Try opening any browsers like Internet Explorer, Google Chrome, Mozilla Firefox and try browsing different websites.

If the websites opening fine, you can proceed with the further resolution steps.

Telnet SMTP port number:

You can use Telnet to test Simple Mail Transfer Protocol (SMTP) communication between messaging servers. SMTP is the protocol that is used to send email messages from one messaging server to another. Using Telnet can be helpful if you are having trouble sending or receiving messages because you can manually send SMTP commands to a messaging server.

To perform the same, refer below steps.

  1. Launch Command Prompt with the Admin privileges.
  2. On the elevated command prompt, you need to enter the telnet command line, which is telnet smtp.servername.com 25.

Suppose, if you are using a Google account, telnet command will be telnet smtp.gmail.com 25.

3. Copy the below command, paste in in Command Prompt and hit enter.

4. You should see the below screen after this. If not, please try to contact your Internet Service Provider.

Now, check if the Outlook works fine. If the issue remains, you can proceed with the further resolution steps.

Check the Outlook email account settings:

To check the email account settings, refer the below steps.

  1. Click on File and click on Account Settings to open the email settings.

2. Next, click on the Email and make a double click on the email address by which you are not able to send emails.

3. In the email settings window click on More Settings button.

4. Go to the Outgoing Server tab and select the My outgoing server (SMTP) requires authentication checkbox. In addition, select the option Use same settings as my incoming mail server.

5. Change Outgoing Server (SMTP) Port number from 25 to 587.

Now, close all the settings and try performing the send/receive and check if the issue with sending reported error 0x8004210B gets fix. If the issue remains, you can proceed with the further resolution steps.

Disable / uninstall Anti-virus program to fix error 0x8004210B:

Faulty or corrupted Anti-Virus program also causes this issue and prevents you in sending and receiving the emails from the Outlook. Therefore, we suggest you try disabling or removing the Anti-Virus program from your computer and check if the Outlook works fine.

You can refer the below links to disable and uninstall Anti-Virus program from your computer.

How to disable Anti-Virus program on Windows 10?

List of Anti-Virus removal tools.

Now, check if the Outlook works fine. In most of the cases, this step fixed the issue and Outlook started working fine.

I hope that the above troubleshooting steps helps you to fix the issue with sending reported error 0x8004210B in Microsoft Outlook and you can send the emails without any further errors. If you need any further assistance, do comments below. We are happy to assist you.

Related Articles:

How to configure IMAP email account in Outlook 2016

This operation has been cancelled due to restrictions in effect on this computer.

How to configure email In Outlook

Leave a Reply

Your email address will not be published. Required fields are marked *