This DBA setting can be used to define the optional password of the system user account who connects to the SMTP_HOST in order to send emails. If no password is given, the email is sent out without transmitting the user/password. This is possible for smtp servers that do not require authentication.
If you try to deliver emails with a null password to a protected server, you will receive a SecurityException: Access to default session denied error. If the user/password is unknown or incorrect, you will get an AuthenticationFailedException error.
Needed for email communication from Smart Materials Portal.