Send an email when custom post type category is changed
Use the hooks added_term_relationship and deleted_term_relationships. These only fire when the relationship changes, as opposed to set_object_terms which always fires: function wpse_181090_object_terms_updated( $object_id ) { static $did = array(); // This function might fire multiple times for the same object, ensure it only runs once if ( ! isset( $did[ $object_id ] ) ) { … Read more