If the email is not being recieved, it means the SMTP Mail Serer address you entered is not correct.
Open the server behaviors panel, Window -> Server Behaviors. In the list of server behaviors double click the Universal Eaml server behavior to edit it.
C;lick the envelope icon in the toolbar to edit the mail server settings.
make sure the correct SMTP server and port are entered here.
If you are unsure what to enter, contact yahoo for details.