Flat vector illustration of a laptop with Outlook error 0x800CCC80, surrounded by icons representing authentication key, SMTP server with lock, checkmark box, and settings gear on a dark blue grid background

Fix: MS Outlook Error 0x800CCC80 – SMTP Authentication Required

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TL;DR: Error 0x800CCC80 means the outgoing mail server rejected your email because authentication was missing or incorrect. The fix is to enable “My outgoing server requires authentication” and verify your login credentials. Jump to Solution 2.

You’re trying to send an email, and Outlook throws a frustrating error:

“Task ‘your email address’ reported error (0x800CCC80): ‘Authentication Required. The server does not support authentication or your account settings need updating.’”

This error specifically targets the outgoing (SMTP) server. It indicates that your email provider requires authentication before sending, but Outlook either isn’t providing it or is using the wrong credentials. The good news—this is usually a quick settings fix.

📌 2026 Note: As of 2026, most major providers (Google, Microsoft, Yahoo) have completely disabled Basic Authentication. If you see this error, it’s often because Outlook is trying to send a simple password string when the server expects a secure token (OAuth2) or an App Password.

What Causes Error 0x800CCC80?

  • SMTP authentication not enabled – The most common cause.
  • Incorrect username/password – Especially after a password change or if using an app password.
  • Wrong authentication method – Some servers require “Use same settings as incoming” while others need a separate login.
  • Modern authentication conflicts – Gmail, Outlook.com, and Office 365 now require OAuth2 or app passwords.
  • Corrupt Outlook profile – Profile corruption can break authentication settings.
  • Outdated Office version – Older versions may not support newer authentication protocols.

How to Fix MS Outlook Error 0x800CCC80

Work through these solutions in order.

1. Verify Your Password & Modern Authentication

Before diving into settings, ensure your credentials are correct.

  • If you have Two‑Factor Authentication (2FA) enabled on your account (Gmail, Outlook.com, Yahoo), a standard password will not work. You must generate an App Password from your account security settings and use that in Outlook.
  • For Microsoft 365 / Exchange accounts: Ensure you’re using OAuth2 authentication. In Outlook, go to File → Account Settings → Account Settings, select your account, click Change, and under Logon Information, choose OAuth2 instead of “Password.”
  • For users on older Outlook versions (pre‑2021) that don’t support OAuth2 natively: The App Password is the only way to fix 0x800CCC80. Generate one from your email provider and use it in place of your regular password.
  • Test your password by logging into webmail (e.g., outlook.com or your provider’s webmail). If you can’t log in there, update your password.

2. Enable SMTP Authentication

This is the most direct fix.

  1. In Outlook, go to File → Account Settings → Account Settings.
  2. Select your email account and click Change.
  3. Click More Settings → Outgoing Server tab.

💡 Pro Tip: If the More Settings button is grayed out, your account was likely added via the Simplified Account Setup in newer Outlook versions. You can access these legacy settings by going to Control Panel → Mail (Microsoft Outlook) → Email Accounts → select your account → Change → More Settings.

  1. Check My outgoing server (SMTP) requires authentication.
  2. Select Use same settings as my incoming mail server (this works for most providers). If that fails, select Log on using and manually enter your email address and password.
  3. Click OK and test sending.

⚠️ Important: Even if the server name and ports are correct, without this box checked, the server will reject your email with error 0x800CCC80.

3. Verify SMTP Ports & Encryption

Incorrect ports or encryption can also trigger authentication failures.

  1. In the same More Settings window, go to the Advanced tab.
  2. Verify the following outgoing server (SMTP) settings:
SettingRecommended Value
Outgoing ServerProvided by your email host (e.g., smtp.gmail.com)
Port587 (STARTTLS) – preferred; 465 (SSL) – alternative
EncryptionSTARTTLS (for 587) or SSL/TLS (for 465)

📌 Note: Port 25 is almost always blocked by residential ISPs to prevent spam. Always use port 587 or 465 for secure, authenticated SMTP.

4. Remove and Re‑add Your Email Account

If settings look correct but the error persists, the account configuration may be corrupted.

  1. Go to File → Account Settings → Account Settings.
  2. Select your email account and click Remove.
  3. Click New to add the account again, entering the correct server settings and authentication details.
  4. When prompted, sign in using the modern browser popup (if available) to ensure OAuth2 tokens are properly established.

5. Run Outlook in Safe Mode & Disable Add‑ins

Some add‑ins can interfere with SMTP authentication.

  1. Press Windows Key + R, type outlook.exe /safe, and press Enter.
  2. If sending works in Safe Mode, disable add‑ins via File → Options → Add‑ins → COM Add‑ins → Go → uncheck all.
  3. Restart Outlook normally and test. Re‑enable add‑ins one by one to find the culprit.

6. Create a New Outlook Profile

Profile corruption can break saved authentication settings.

  1. Close Outlook.
  2. Open Control Panel → Mail (Microsoft Outlook) → Show Profiles.
  3. Click Add, create a new profile, and set up your email account with correct SMTP settings.
  4. Under “When starting Microsoft Outlook,” select Prompt for a profile.
  5. Open Outlook with the new profile and test sending.

7. Use the Microsoft Support and Recovery Assistant (SaRA)

SaRA can automatically diagnose and fix SMTP authentication issues.

  1. Download the Microsoft Support and Recovery Assistant.
  2. Run the tool and select Outlook → I’m having trouble sending or receiving email.
  3. Follow the prompts. SaRA will test your SMTP settings and suggest repairs.

8. Check with Your Email Provider or IT Admin

If none of the above work, the problem may be server‑side:

  • Personal accounts: Contact your email hosting provider. Ask if SMTP authentication is required and confirm the correct server name, ports, and authentication method (password vs. OAuth2).
  • Work/school accounts: Your IT department may have SMTP AUTH disabled at the tenant level for security reasons. No amount of local settings can fix that. They can enable it for your account or provide alternative sending methods.

Related Reading from Mukunda Software

Explore our other Outlook troubleshooting guides for comprehensive help:

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