hi

Yes, As per my understanding it is possible to send email to all the register please follow below steps.

• Create one server action and add aggregate into that action which contain all the registered user list.
• Get that list of registered users into for each loop.
• Crete one email template into it or you can drag and drop from tool box and pass registered user email to To property of email template.
• And Trigger that action when to update Application.

And also you can pass comma separated list and pass into To property list.

Regards,

Pawan