To create a new-user greeting use the command line:
configutil -o gen.newuserforms -v Message
Where Message must contain a header (with at least a subject line), followed by $$, then the message body. The $ represents a new line.
For example, to enable this parameter, you can set the following configuration variables:
configutil -o gen.newuserforms -v ’Subject: Welcome!! $$ Sesta.com welcomes you to the premier internet experience in Dafandzadgad!
Depending on the shell that you are using, it might be necessary to append a special character before $ to escape the special meaning of $. ($ is often the escape character for the shell.)