The Yahoo! Mail SMTP server requires authentication. To learn how to configure your email application, please choose from the following supported applications:

• Outlook 2002 (XP) and 2003
• Outlook 98 and 2000
• Microsoft Outlook Express
• Microsoft Outlook Express for Macintosh
• Entourage 2001 and higher
• Eudora 5.1 and higher
• IncrediMail build 618 and higher

Please make sure that you've entered your Yahoo! Mail address as the "From" address in your email client. You won't be able to send mail if you've entered another address.

If you have the Norton AntiVirus email feature enabled, you might have to do additional configuration to use Outlook or Outlook Express. For more information, please visit the Symantec web site.

If you've tried the above steps and continue to have problems, your ISP might not allow its users to send messages with other companies' SMTP outgoing mail servers.

If you're unable to send email, try using port 587 when sending via Yahoo!'s SMTP server. Here's how to make this change in Outlook:

1. From the "Tools" menu, select "Accounts."
2. Select your Yahoo! POP account and click the "Properties" button.
3. Click the "Advanced" tab.
4. Next to "Outgoing server (SMTP"), change port 25 to 587.
5. Click "Apply." Then click "OK" and "Close."