Hi,
if (method=="INVITE") { if (!lookup(location)) {
sl_send_reply(404,"Not authorized"); break;
} }
This one checks if the *called* party is registered at SER, not the *calling* party.
However, I don't see a sense in restricting outgoing calls only to registered users. You can authenticate the caller using proxy_authorize() anyway. If the user doesn't register, he just cannot be called.
Andy