If you've made changes to your Thank You email template but they are not being reflected in your tests then you are most likely using free checkouts to test, which would trigger the Free Purchase Thank You email instead of the regular Thank You email that goes out with paid purchases.
To test out the new Thank you email you can:
- Make a real purchase and refund yourself afterwards.
- Use your payment processors test options if they offer any (Stripe offer test API credentials for this purpose).
- Try our Test Credit Card Processor to simulate a paid purchase, you can read about setting that up here.
If you use the test credit card processor or your payment processors test options be sure to disable them after you are done testing so that your customers don't encounter them.