Stripe (Pay with card):
If you made a purchase using your credit card, you will have received a receipt from Stripe to the email address you provided during the checkout process. If you are unable to find the email by browsing for it, try performing a search. The receipt will have the following subject line:
Subject line: "Your Humble Bundle, Inc. receipt [#XXXX-XXXX-XXXX]" (The X's represent Stripe's receipt number)
From: Humble Bundle, Inc.