0x800CCC0F error in outlook2016 win10 ,how to solve this problem ？

Hi jiangzhaoyan1227,

here are the steps you can use:

1. Verify Your Internet Connection: Ensure your internet connection is stable.

2. Disable Antivirus Software: Temporary disable any antivirus software that may interfere with Outlook's email operations.

3. Turn Off Windows Firewall: Disable the Windows Firewall temporarily to check if it's causing the issue.

4. Adjust Server Timeouts in Outlook: Increasing server timeout settings within Outlook could help resolve the problem.

5. Use Outlook Safe Mode: Running Outlook in safe mode can help identify if any add-ins are causing the error.

6. Repair Outlook PST Files: If previous steps don't resolve the issue, consider repairing your Outlook PST files.

More detailed instructions you can find here:
Error occurs when you send or receive an email message in Outlook or Outlook Express - Microsoft Support