I had this working in classic so I assume you could do it here.
More steps involved with threads.
Just register a bogus user. Use a nice name because it will appear in the email.
You may need to place the bogus user in a custom group so you can prohibit some functions like private messages bla bla.
Then login as the bogus user.
Edit mystuff to watch forums and select to send email notification.
Note when you register the bogus user you may not want to use the discussion email address until you have it working.
Due to emails sent for validation etc.
Then goto the control panel edit the bogus user and change the email address.
Note: I am sure I missed a couple of settings you may want to disable since this is not a real user.
