@cjay
If tickets.email is a redirect, where is that defined?
@ntozier just told you, it's defined here:
url_post("^/tickets\.(?P<format>xml|json|email)$", array('api.tickets.php:TicketApiController','create'))
It goes from browser, to api/.htaccess (URL rewrite), to api/http.php, to inclue/api.tickets.php. Just follow the code.
Cheers.