It seems to be impossible to create account only via the http port with sparkweb.
I have been configured my sparkweb to be accessed via http port (80) but only the login is possible, create account other ports.
So when a user is behind a proxy or firewall he can't create account !
But if the user has create his account before (from his home for example) he can login behind the firewall.
Please explain me how to configure sparkweb to be able to create account only with http ports