Send mail when a post is published

Hello guys
I want to implement a function which, when a new post is created , controls all the request-posts (post_type=request, which is a post type I created in my WP site), and if the new post (post_type=post) has some custom fields equals to the request-post that is created before, then it just send a mail to an email address.

Until now, I’ve implemented this in the functions.php, but with no results:

function wpr_authorNotification($post_ID) {
   $post = get_post($post_ID);
   $manufacturer=get_post_meta($post->ID, 'Manufacturer', true);
   $message = "
      Hi ".echo get_post_meta($post->ID, 'wpcf-request_client_name', true).",
      Your post, ".$post->post_title." has just been published. Well done!
   ";
global $request;
$args = array( 'post_type' => 'requests', 'post_status'=> 'publish' );
$myrequests = get_posts( $args );

foreach( $myrequests as $request ) {
setup_postdata($request);
if (  $manufacturer == get_post_meta($request->ID, 'wpcf-article-manufacturer', true)  )
{
mail(get_post_meta($request->ID, 'wpcf-request_client_email', true), "Your article is online", $message);
}
}
}
add_action('publish_post', 'wpr_authorNotification');

How can I change the code?