All ShopSite stores that were version 6.2.1 have had a patch applied that resolves an email issue if a customer enters an invalid email address. Previously, an error page would appear to the customer upon checkout (if they entered an invalid email address), but the order would still go through. The customer might not realize this and try and replace the order, resulting in duplicate orders.

This has been corrected so that the customer will see the receipt page as normal, with a warning at the top about their email address possibly being incorrect. Note, however, that since the email address may be incorrect the shopper and/or the merchant still may not receive the email receipt.

More details can be found at:
http://support.shopsite.com/kbase/view_answer.php?questionID=S5465

- LexiConn Support