The connection to the server has failed. Error Number: 0x800CCC0E.

The error code 0x800CCC0E in Microsoft Outlook and Outlook Express indicates that the connection to the mail server failed or was interrupted. This can happen due to a variety of reasons such as incorrect server settings, network issues, or interference from security software. Here are steps to troubleshoot and resolve this error:

1. Verify Email Account Settings

Ensure your email account settings are correct. Double-check the following:

• Incoming mail server (POP3 or IMAP) and outgoing mail server (SMTP) addresses
• Port numbers: Commonly, POP3 uses port 110 or 995, IMAP uses port 143 or 993, SMTP uses ports 25, 26, 465, or 587
• SSL/TLS settings
• Email account username and password

2. Check Internet Connection

Ensure you have a stable and active internet connection. Test your connection by browsing the internet or using another online service.

3. Disable Firewall and Antivirus Temporarily

Sometimes, firewalls or antivirus software can block Outlook from connecting to the mail server. Temporarily disable these to see if the issue is resolved. Make sure to re-enable them after testing.

4. Increase Server Timeouts

Increasing the server timeout setting can help if the server is slow to respond:

1. Go to File > Account Settings > Account Settings.
2. Select the email account and click on Change.
3. Click on More Settings.
4. Go to the Advanced tab.
5. Increase the server timeout slider.

5. Repair Outlook Profile

A corrupted Outlook profile can cause this error. Create a new profile and test if it resolves the issue:

1. Go to Control Panel > Mail.
2. Click on Show Profiles.
3. Click on Add to create a new profile.
4. Configure your email account in the new profile.
5. Set the new profile as the default and test.

6. Check Router and Network Configuration

Ensure your router and network are not blocking the email server's ports. Verify that the necessary ports (110, 143, 995, 993, 25, 26, 465, 587) are open.

7. Use Safe Mode

Start Outlook in safe mode to determine if add-ins are causing the issue:

1. Close Outlook.
2. Open the Run dialog (Win + R), type outlook.exe /safe, and press Enter.
3. If the error does not occur in safe mode, disable add-ins one by one to identify the culprit.

8. Update Outlook

Ensure you have the latest updates for Outlook. Microsoft often releases patches and updates that fix known issues.

9. Reinstall Outlook

If none of the above steps work, consider reinstalling Outlook. This can resolve any underlying software issues.

10. Contact Your Email Provider

If the problem persists, contact your email service provider. There might be an issue on their end or specific settings required for your account.

11. Check for ISP Blocking

Some Internet Service Providers (ISPs) block certain ports to reduce spam. If you are using port 25 for SMTP, try using port 587 or 465 instead.

12. Verify Server Availability

Make sure the email server is not down for maintenance or experiencing issues. You can often check this on the service provider's status page.

Summary

By systematically verifying your settings and checking for network and software conflicts, you should be able to diagnose and resolve the 0x800CCC0E error in Outlook. If the problem continues, it may be necessary to seek further support from your email service provider or IT professional.