Microsoft Outlook — Error 0x800CCC0E — What It Means & How to Fix It

What Does This Error Mean?

Error 0x800CCC0E means Outlook tried to connect to your email server but the connection was refused or timed out. It usually appears when you try to send or receive emails. The most common cause is incorrect server settings — particularly the wrong port number or server address.

Affected Models

Microsoft Outlook 2016
Microsoft Outlook 2019
Microsoft Outlook 2021
Microsoft 365 Outlook

Common Causes

The outgoing mail server (SMTP) port number or server address is wrong in your account settings
Your internet connection dropped or is unstable while Outlook was trying to connect
A firewall or antivirus program is blocking Outlook from reaching the email server
The email server itself is temporarily down or undergoing maintenance
SSL/TLS encryption settings do not match what the server requires

How to Fix It

Check your internet connection first. Open a browser and load any website. If the internet is not working, fix that before troubleshooting Outlook.

Outlook cannot connect to any email server if your internet is down.
Verify your SMTP server settings. Go to File > Account Settings > Account Settings. Double-click your email account, then click More Settings > Outgoing Server. Make sure the port is 587 (with TLS) or 465 (with SSL).

Port 25 is commonly blocked by ISPs to prevent spam. If you are using port 25, switch to 587 immediately.
Temporarily disable your antivirus email scanning. Many antivirus programs scan emails as they pass through, which can break the connection. Look for email scanning or email protection in your antivirus settings.

After disabling, try sending a test email. If it works, add Outlook as an exclusion in your antivirus settings.
Check if your email provider's server is down. Visit downdetector.com and search for your email service. If others are reporting problems, wait 30–60 minutes and try again.

Server outages are outside your control. Waiting is the only fix when the server itself is the problem.
Remove and re-add your email account in Outlook. Go to File > Account Settings, select your account, click Remove, then add it again from scratch using your email provider's recommended settings.

This is the cleanest fix when settings have become corrupted over time. You will not lose emails stored on the server.

When to Call a Professional

If you cannot figure out the correct server settings, contact your email provider's support team. For business email, contact your IT department — they will have the exact server settings. For home users with ISP-provided email (like Comcast or AT&T), call your ISP's support line.

Frequently Asked Questions

What is the difference between 0x800CCC0E and 0x800CCC0F?

Both are Outlook connection errors, but they point to slightly different problems. 0x800CCC0E means the connection to the mail server was refused or failed to establish. 0x800CCC0F means the connection was made but then dropped unexpectedly mid-session. Both errors often have the same root causes — wrong settings, firewall blocks, or a flaky internet connection.

What SMTP port should I use for Gmail in Outlook?

For Gmail: use smtp.gmail.com as the server, port 587, with TLS encryption. Alternatively, use port 465 with SSL. Make sure you have enabled 'less secure app access' or set up an App Password in your Google account settings if you are not using OAuth.

My settings look correct but I still get this error. What else can I try?

A few other things to check: Make sure your account password has not expired or been changed recently. Check if your email account has been temporarily locked due to too many failed login attempts. Try accessing your email through a web browser to confirm the account itself is working. If everything works in the browser but not Outlook, the problem is definitely in Outlook's settings.