[JWait]

To stop the initial email from being sent (although I do not recommend it) you can modifiy include/func/func.order.php. Look for the section marked "This function change order status in orders table".

Find where it says "db_query("UPDATE $sql_tbl[orders] SET status = 'Q' WHERE orderid = '$orderid'");"
Just under that line, change $send_notification = true; to false. I think that should do it, but test to make sure.

To be honest, if you are not using the "processed" function, it would be easier to just uncheck the "email customer" in the admin section so they would not get this email. The customer would receive the initial email which contains all of the information about their order, then the email from Worldpay once their credit card is charged. The only difference is the "this is order notification #no 1" and "Dear Mr Customers first and second name. Thanks for placing your order. Please come back soon." which are just "language" labels and text that can be changed... I suggest "Thank you for your order #no1" for the initial email, "Thank you for shopping with us. Below is your order receipt." which can be changed by look for "order notification" and "thank you" in the languages section. Its much easier to do, and much easier to undo if sometime in the future you need the initial email sent for some other reason (like payment by money order for instance)