woocommerce-add-email-cc-if-order-contains-product-category-tag.php

<?php
/**
 * Modified from https://www.skyverge.com/blog/add-woocommerce-email-recipients-conditionally/
 * 
 * Add another email recipient for admin New Order emails if a product from a specific category or with a specific tag is ordered
 *
 * @param string $recipient a comma-separated string of email recipients (will turn into an array after this filter!)
 * @param \WC_Order $order the order object for which the email is sent
 * @return string $recipient the updated list of email recipients
 */
function sv_conditional_email_recipient( $recipient, $order ) {
	// Bail on WC settings pages since the order object isn't yet set yet
	// Not sure why this is even a thing, but shikata ga nai
	$page = $_GET['page'] = isset( $_GET['page'] ) ? $_GET['page'] : '';
	if ( 'wc-settings' === $page ) {
		return $recipient; 
	}
	
	// just in case
	if ( ! $order instanceof WC_Order ) {
		return $recipient; 
	}
	$items = $order->get_items();
	
	// check if product from category or with tag is in order
	foreach ( $items as $item ) {
		$product = $order->get_product_from_item( $item );
		$args = array('orderby' => 'name', 'order' => 'ASC', 'fields' => 'names');
		$product_cats = wp_get_post_terms( $product->get_id, 'product_cat', $args ); // could swap product_cat for product_tag
		// add our extra recipient if there's a product from the category with slug "dieta" - commas needed!
		// we can bail if we've found one, no need to add the recipient more than once
		if ( $product && in_array( "dieta", $product_cats ) ) {
			$recipient .= ', [email protected]';
			return $recipient;
		}
	}
	
	return $recipient;
}
add_filter( 'woocommerce_email_recipient_new_order', 'sv_conditional_email_recipient', 10, 2 );

hello Steve,
Where I can put this codes?
and where i can call the function?
Thanks.

I know this answer is late, but might help someone else. This code is placed in the functions.php file of your wordpress theme.

This, unfortunately, did not work for me (Wordpress 4.9.5 and WC 3.3.5)