Knowledgebase
How to fix the SMTP error 0x800CCC7D in Outlook 2003
If you mark the SSL checkbox for the outgoing (SMTP) server from your email account settings in Microsoft Outlook 2003 (Service Pack 1) and you set the port number to 587, you'll get the following error message:
Task 'server_name.com'-Sending' reported error (0x800CCC7D): 'Your outgoing (SMTP) server does not support SSL-secured connections. If SSL-secured connections have worked in the past, contact your server administrator or Internet service provider (ISP).'
The encryption port number for SSL/TLS is actually 465 and not 587, but Outlook 2003 is also supposed to support STARTTLS which works on port 587. STARTTLS is a command for upgrading a non-encrypted connection to an encrypted one. However, the oldest version of Outlook 2003, which is Service Pack 1, has some issues with STARTTLS. So the solution to this problem is either to upgrade your Outlook, or to set the port number to 465 (with encryption enabled).
You'll also get the same error code (0x0800CCC7D) when sending mail with Outlook 2003, if you're disconnected from the Internet. So make sure that's not the case.
Also make sure all the rest of the settings for the email account are correct, e.g. server names, SMTP authentication, etc. If needed, delete the account and recreate it.
Check whether your antivirus/firewall software scans email messages and disable that scan. This is a common cause for many email errors.
Some users of Outlook have also reported that they managed to solve this error by clearing the SSL cache. To clear the SSL cache close your email client, click on the Windows Start button in the lower left corner of you screen, then go to Control Panel>Internet Options. On the Internet Properties window that opens click on the Content tab and then on the button Clear SSL state.
If you need help with configuring Outlook 2003, check out the tutorial.