You can get feedback on your submissions at the feedback page http://www.cipher.maths.soton.ac.uk/feedback.php which is also linked from the Leader Boards. In general we delay feedback until after the next points boundary so if you wait for the feedback rather than correct your own mistakes you will lose points, but for Challenge 1 we have started the feedback early so you can still get full marks for Challenge 1 even though we are giving you a hint. This should be better than the old email feedback system as it does not rely on the emails getting through. To be clear there is no email feedback this year.