The 0x800CCC0B error when trying to send email through outlook express is a common error that is often encountered on an attempt to send your first email from third party email services such as gmail (google mail) using outlook express. The POP account may appear to work fine and you are able to receive email without a problem. This is because the SMTP 0x800CCC0B error will only occur when sending email.
An unknown error has occurred. Subject 'test', Account: 'pop.gmail.com', Server: 'smtp.gmail.com', Protocol: SMTP, Port: 465, Secure(SSL): Yes, Error Number: 0x800CCC0B
This error can occur because your email provider does not allow messages to be sent via (SMTP) without server authentication. The fix is relatively easy and is outlined in the following simple solution:
How to Fix the 0x800CCC0B Outlook Express error:
From Outlook Express, navigate to Tools > Accounts
Select the account that is encountering the error from the list and then click Properties
Navigate to the Servers tab and check the My server requires authentication box under Outgoing Mail Server, then click OK
Now, simply try to resend the email by clicking the Send/Recv button
If all goes well, you should now be able to send email!