is caused by a misconfiguration in the setup of the mail client. In
order to rectify this problem, you can follow the steps below double
check on the settings.
1. Go to 'Tools' --> choose Accounts (or E-mail accounts).
2. Double-click on the entry for your e-mail account (usually listed as mail.yourdomain.com)
3. Go to the 'Servers' tab. REMOVE the tick from the box labeled "Log on using Secure Password Authentication"
4. Click on the OK button, and then 'Close' to return to Outlook Express.