<?php // only copy this line if needed

/**
 * Function adds a BCC header to emails that match our array
 * 
 * @param string $headers The default headers being used
 * @param string $object  The email type/object that is being processed
 */
function add_bcc_to_certain_emails( $headers, $object ) {

	// email types/objects to add bcc to
	$add_bcc_to = array(
		'customer_renewal_invoice',		// Renewal invoice from WooCommerce Subscriptions
		'customer_processing_order',	// Customer Processing order from WooCommerce
		);

	// if our email object is in our array
	if ( in_array( $object, $add_bcc_to ) ) {

		// change our headers
		$headers = array( 
			$headers,
			'Bcc: Me <me@example.com>' ."\r\n",
			);
	}

	return $headers;
}
add_filter( 'woocommerce_email_headers', 'add_bcc_to_certain_emails', 10, 2 );