Uses WP's is_email() to validate email addresses in Subscriber model

lib/Models/ModelValidator.php

@@ -0,0 +1,30 @@
+<?php
+
+namespace MailPoet\Models;
+
+if(!defined('ABSPATH')) exit;
+
+class ModelValidator extends \Sudzy\Engine {
+  public $validators;
+
+  function __construct() {
+    parent::__construct();
+    $this->validators = array(
+      'validEmail' => 'validateEmail'
+    );
+    $this->setupValidators();
+  }
+
+  private function setupValidators() {
+    $_this = $this;
+    foreach($this->validators as $validator => $action) {
+      $this->addValidator($validator, function($params) use ($action, $_this) {
+        return call_user_func(array($this, $action), $params);
+      });
+    }
+  }
+
+  function validateEmail($email) {
+    return is_email($email) !== false;
+  }
+}