I see, that helps. I wonder what we could do in that case, when you need a user to sign up with a specific email address. One idea is:
http://meta.discourse.org/login
This works to drop a user on the login page but what if..
http://meta.discourse.org/login?email=name@example.com
Adding the email address as a param, did the exact same thing but pre-populated the user field with the desired email address? @neil what do you think of this?