What action triggers a confirmation email for a PayPal Express payment?

In the context of PayPal Express payments within Magento, the action that triggers a confirmation email is related to the completion of the transaction process. When a customer clicks the Purchase button, it indicates that they have finalized their order and are confirming their intention to buy. At this point, the system processes the payment and completes the order, which then initiates the sending of a confirmation email.

The confirmation email serves as a record for the customer, providing details of the transaction, including the order summary and payment confirmation. It's an important aspect of the e-commerce experience, ensuring that buyers have clear communication regarding their purchases.

Other actions, such as logging into the PayPal account or clicking the Checkout button, are part of the payment process but do not directly trigger the confirmation email. Finalizing shipping details is also necessary for completing an order, but it is the act of clicking the Purchase button that signifies the completion of the transaction, ultimately leading to the confirmation email being sent.