I have an issue with the PayPal integration. For quite a while all order confirmation emails were working with no problems. Recently if a customer uses paypal express checkout, they no longer receieve the order confirmation email. If the customer uses a card they get it with no problems. Both payment methods are part of the PayPal Payments Pro integration.
Any help on how to get to the bottom of this would be gratefully appreciated. PayPal have been useless on their support with this, which is a tad worrying.