I would like recipients of submission not to see other email addresses the submission is sent to

Any progress on this since? I would like recipients of submission not to see other email addresses the submission is sent to.

This is not one of the available features since you can send the email directly (TO header) and including multiple people (CC), while the log is created for each submission email sent, so that you can see it and confirm if the email is sent or not - since I presume that this is what you are after.

Now to accomplish what you are after you can simply create a new email notification that is sent to that 'hidden' email address.

This allows you to easily change the email address and the content to match what you are after, while also allows you to send an email to someone whom will not be seen by others who got a message from another email template.

So next to your current email notifier, all you should do is set a new one: Setting Up Email Notifications