I am having problems with my Wordpress installation, or WooCommerce to be more specific.
The client I've been working for the last couple of months, wants that every time a customer completes/pays an order, a custom email is sent to his email address, besides the standard order confirmation email.
In short: I need to send a custom email to the customer when the order is completed. How can I do that inside the functions.php?
I tried using various hooks and functions described in the official documentation, but couldn't figure it out.
The Wordpress version is 3.8.1, and WooCommerce is version is 2.0.20.
Thank You in advance.