Cleveness ToDo not showing

Looks like Cindy answered your question. However, I would make the following changes:

function my_postie_post_function($post) {

  add_post_meta($post['ID'], '_status', 0);
  add_post_meta($post['ID'], '_priority', 1); 

}

add_action('postie_post_after', 'my_postie_post_function');

Thanks, Wayne. The above is very similar to what I did, save one line. Are you saying that I shouldn’t return the post?

postie_post_after is an action not a filter so you should call add_action and not return anything.

Thank you, sir!