Help Yahoo mail and error with settings

[upsavr]

Hello
I was using engadget and tried to send an article to a friend via email. Now my phone keeps coming back saying the account setting are wrong and the email can't be sent. I can't figure out why the message can't be sent and how to get it to stop.
Also, I have sent a test email through the mail widget that I have yahoo loaded on and that still works.

Thanks