Outlook express error 554 error : 0x800ccc79

Hello how to fix: 554 access denied error 0x800CCC79

Via outlook I can not send messages to wanadoo messaging (which is my provider) ... But through wanadoo page, I can send messages to ttes messaging. I made a restaurant without success.
I am using Windows XP ... Is there a simple solution (such as outlook uninstall and reinstall) because I do not know anything computer .... Help!
Thank you in advance,

This is a simple problem with your mail server configuration.

1. Launch Outlook Express.
2. Delete the contents of your Outbox.
3. Click the Tools menu, then Accounts. Select the Mail tab, then select the mail account causing the problem.
4. Click Properties.
5. Select the Servers tab.
6. In the Outgoing mail (SMTP) field, make sure the server name is smtp.free.fr. If this is not the case, type it, in small letters.
7. Click OK to validate your changes.

Thank you for your reply, anyother suggestions are still welcome and will be appreciated...