Error 0x800CCC67 is caused by the SMTP (Protocol) usually in Windows Live Mail and in Outlook. This indicates that the message you were trying to send could not be sent and as a result “An unknown error has occurred.” pop-up appears. Generally, the most common reason for this error to occur is when your e-mail provider changes (ssl or port) settings; or if your Windows (Anti-Virus) / (Firewall) denies access to the SMTP.
In this guide; i will walk you through a couple of steps to address this issue.
Method 1: Disable your anti-virus / firewall temporarily:
Which ever antivirus software you’re using should be turned off. Since there are a couple of anti-virus other there with different steps to disable; i will walk you through the general steps that should allow you to figure out how to disable the one you’re running.
In most cases; AV can be disabled via it’s icon in the tray on the lower right corner where the clock is. You will need to pull up it’s menu to see the options which you can by taking your mouse to the corner over the icon and (right-clicking on it); once done you should see the options. Use the appropriate option to disable it. Below is a sample screen for disabling AVG.
After disabling your AV software; go back to Windows Live Mail or Outlook and try sending an e-mail. If the previously sent message is stucked; press F9 key to do a send/receive all. Test to see if this fixes the issue if not; then proceed to Method 2. Your Anti Virus software should stay disabled until we do the last method.
Method 2: Change the SMTP Port:
Now let’s check if the port we’re using is correct. Go to this website Check Email Settings and type in your e-mail address. Look for the port under Outgoing Mail Server. Once you have the port; change it in your e-mail client.
For Windows Live Mail follow the steps here
For Outlook follow the steps here
After the port is changed; press F9 or try to send again. If the e-mail still won’t go out; power off your router for 1 minute and then power it back on to test again.
If the method above still wouldn’t fix the issue; then proceed with Method 3.
Method 3: Repair & Create New Profile
For Windows Live Mail: see steps here on how to repair it.
For Outlook: see steps here on how to create a new profile
Hopefully this should get you up and running. Once you get it fixed – re-enable your anti-virus by repeating the same steps as you did earlier; this time you will see the option to enable it.