Hi,
This error is comming from your SMTP mail server and is being propogated into the UTL_SMTP package. Typically this error indicates that you are not using the correct email server name in the UTL_SMTP.OPEN_CONNECTION() call. An easy way to determine your correct email host is to review your email client configuration. If you are using Netscape, for example, you would check under 'preferences' then 'mail servers' to find this information.

Regards,
Rohit Nirkhe,Oracle/Apps DBA,OCP 8i
[email protected]