Do you mean Outlook Express?  Your outgoing mail server isn't configured properly.

Refering to Outlook express....web site supplying info and refering me to send e mail...but when e mail is sent with Outlook Exprewss >>I receive message .....cannot locate Yahoo???????

I am clueless as to what you are doing.

What website?  What does refering me to send e mail mean? I don't understand what this means.