For email configuration, how can you set the SMTP Username and Password to blank instead of "none"?

We are working on setting up the email settings on the JTS server.  Our SMTP server does not require credentials.  The IBM Rational Help page for email settings states that "if no credentials are needed, you can leave the user name and password blank".  It will not allow us to save the email settings page with those two fields blank.  If we put "none" in the SMTP Username and Password fields, it comes back with a "User Authentication Failure" with a message "connecting to server (our server name)  : -1 for user none".  Therefore, it appears to be trying to authenticate using the user name "none".  How can we set the SMTP Username and Password to be blank instead of "none"?