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0x800CCC0DOfficeHigh

Error 0x800CCC0D — Outlook Server Not Found | Microsoft Office Fix

Microsoft 365Office 2021Office 2019Office 2016

What Does 0x800CCC0D Mean?

Outlook cannot find the specified mail server. The server hostname cannot be resolved to an IP address.

Real-World Causes

  1. 1Incorrect mail server hostname in account settings
  2. 2DNS server not resolving the mail server name
  3. 3Internet connection is down
  4. 4VPN disconnected and mail server is on internal network

Symptoms

  • ⚠Cannot send or receive any emails
  • ⚠Error message mentions server not found
  • ⚠Outlook status bar shows 'Disconnected'
  • ⚠All Send/Receive attempts fail immediately

DIY Fix

Beginner-friendly steps you can try at home

  1. 1Verify internet connection is working (browse a website)
  2. 2Double-check mail server address in account settings
  3. 3Try using the mail server's IP address instead of hostname
  4. 4Restart your router/modem to refresh DNS

Advanced Fix

For experienced users and IT professionals

  1. 1Flush DNS cache: open Command Prompt as admin, run 'ipconfig /flushdns'
  2. 2Try alternative DNS servers (Google: 8.8.8.8 or Cloudflare: 1.1.1.1)
  3. 3Use nslookup to test DNS resolution of the mail server
  4. 4Check hosts file for incorrect entries: C:\Windows\System32\drivers\etc\hosts

Frequently Asked Questions

How do I find my correct mail server address?
Check your email provider's help documentation. Common examples: Gmail uses smtp.gmail.com / imap.gmail.com. Outlook.com uses smtp-mail.outlook.com / outlook.office365.com. Your IT department can provide corporate server details.
Why did the server suddenly stop being found?
Possible causes: ISP DNS issues, your email provider changed server addresses, VPN disconnection, or local DNS cache corruption. Try flushing DNS and checking your provider's status page.

Related Error Codes

0x800CCC0EOutlook Connection Failed0x800CCC19Timeout Waiting for Server0x80042108Outlook Receiving Timeout

About the Author

Windows Troubleshooting Team

Verified against official Microsoft documentation and real-world diagnostic data. Error behavior confirmed across Windows 10, Windows 11, and Windows Server.