Triggered before an email notification is sent to a customer.
The event handler can override some variables before the message is sent. The handler function should return
an associative array containing variable names and values. The supported variables are:
public function subscribeEvents()
{
Backend::$events->addEvent('core:onBeforeEmailSendToCustomer', $this, 'before_email_send_to_customer');
}
public function before_email_send_to_customer($customer, $subject, $message_text, $customer_email, $customer_name, $custom_data, $reply_to)
{
$result = array(
'reply_to'=>array('john@example.com'=>'John Smith')
);
return $result;
}