diff --git a/RoboFile.php b/RoboFile.php
index 00c4f2838d..962ae702db 100644
--- a/RoboFile.php
+++ b/RoboFile.php
@@ -370,7 +370,7 @@ class RoboFile extends \Robo\Tasks {
         'php -d memory_limit=2G '.
         "$dir/phpstan.phar analyse ".
         "--configuration $dir/tasks/phpstan/phpstan.neon ".
-        '--level 0 '.
+        '--level 1 '.
         "$dir/lib"
       )
       ->dir(__DIR__ . '/tasks/phpstan')
diff --git a/lib/API/JSON/v1/Forms.php b/lib/API/JSON/v1/Forms.php
index e420f19638..3c74d77a4b 100644
--- a/lib/API/JSON/v1/Forms.php
+++ b/lib/API/JSON/v1/Forms.php
@@ -172,6 +172,7 @@ class Forms extends APIEndpoint {
     // check if the user gets to pick his own lists
     // or if it's selected by the admin
     $has_segment_selection = false;
+    $list_selection = [];
     foreach($body as $i => $block) {
       if($block['type'] === 'segment') {
         $has_segment_selection = true;
diff --git a/lib/API/JSON/v1/MP2Migrator.php b/lib/API/JSON/v1/MP2Migrator.php
index aa3bd41d75..96967e6f33 100644
--- a/lib/API/JSON/v1/MP2Migrator.php
+++ b/lib/API/JSON/v1/MP2Migrator.php
@@ -11,6 +11,7 @@ class MP2Migrator extends APIEndpoint {
   public $permissions = array(
     'global' => AccessControl::PERMISSION_MANAGE_SETTINGS
   );
+  private $MP2Migrator;
 
   public function __construct() {
     $this->MP2Migrator = new \MailPoet\Config\MP2Migrator();
diff --git a/lib/Config/MP2Migrator.php b/lib/Config/MP2Migrator.php
index 53db4b8fce..3bec6bf3ab 100644
--- a/lib/Config/MP2Migrator.php
+++ b/lib/Config/MP2Migrator.php
@@ -25,6 +25,14 @@ class MP2Migrator {
   private $segments_mapping = array(); // Mapping between old and new segment IDs
   private $wp_users_segment;
   private $double_optin_enabled = true;
+  private $mp2_campaign_table;
+  private $mp2_custom_field_table;
+  private $mp2_email_table;
+  private $mp2_form_table;
+  private $mp2_list_table;
+  private $mp2_user_table;
+  private $mp2_user_list_table;
+
 
   public function __construct() {
     $this->defineMP2Tables();
@@ -37,27 +45,33 @@ class MP2Migrator {
   private function defineMP2Tables() {
     global $wpdb;
 
-    if(!defined('MP2_CAMPAIGN_TABLE')) {
-      define('MP2_CAMPAIGN_TABLE', $wpdb->prefix . 'wysija_campaign');
-    }
-    if(!defined('MP2_CUSTOM_FIELD_TABLE')) {
-      define('MP2_CUSTOM_FIELD_TABLE', $wpdb->prefix . 'wysija_custom_field');
-    }
-    if(!defined('MP2_EMAIL_TABLE')) {
-      define('MP2_EMAIL_TABLE', $wpdb->prefix . 'wysija_email');
-    }
-    if(!defined('MP2_FORM_TABLE')) {
-      define('MP2_FORM_TABLE', $wpdb->prefix . 'wysija_form');
-    }
-    if(!defined('MP2_LIST_TABLE')) {
-      define('MP2_LIST_TABLE', $wpdb->prefix . 'wysija_list');
-    }
-    if(!defined('MP2_USER_TABLE')) {
-      define('MP2_USER_TABLE', $wpdb->prefix . 'wysija_user');
-    }
-    if(!defined('MP2_USER_LIST_TABLE')) {
-      define('MP2_USER_LIST_TABLE', $wpdb->prefix . 'wysija_user_list');
-    }
+    $this->mp2_campaign_table = defined('MP2_CAMPAIGN_TABLE')
+      ? MP2_CAMPAIGN_TABLE
+      : $wpdb->prefix . 'wysija_campaign';
+
+    $this->mp2_custom_field_table = defined('MP2_CUSTOM_FIELD_TABLE')
+      ? MP2_CUSTOM_FIELD_TABLE
+      : $wpdb->prefix . 'wysija_custom_field';
+
+    $this->mp2_email_table = defined('MP2_EMAIL_TABLE')
+      ? MP2_EMAIL_TABLE
+      : $wpdb->prefix . 'wysija_email';
+
+    $this->mp2_form_table = defined('MP2_FORM_TABLE')
+      ? MP2_FORM_TABLE
+      : $wpdb->prefix . 'wysija_form';
+
+    $this->mp2_list_table = defined('MP2_LIST_TABLE')
+      ? MP2_LIST_TABLE
+      : $wpdb->prefix . 'wysija_list';
+
+    $this->mp2_user_table = defined('MP2_USER_TABLE')
+      ? MP2_USER_TABLE
+      : $wpdb->prefix . 'wysija_user';
+
+    $this->mp2_user_list_table = defined('MP2_USER_LIST_TABLE')
+      ? MP2_USER_LIST_TABLE
+      : $wpdb->prefix . 'wysija_user_list';
   }
 
   /**
@@ -78,7 +92,7 @@ class MP2Migrator {
     if(Setting::getValue('mailpoet_migration_complete')) {
       return false;
     } else {
-      return $this->tableExists(MP2_CAMPAIGN_TABLE); // Check if the MailPoet 2 tables exist
+      return $this->tableExists($this->mp2_campaign_table); // Check if the MailPoet 2 tables exist
     }
   }
 
@@ -272,17 +286,17 @@ class MP2Migrator {
     $result .= __('MailPoet 2 data found:', 'mailpoet') . "\n";
 
     // User Lists
-    $users_lists_count = \ORM::for_table(MP2_LIST_TABLE)->count();
+    $users_lists_count = \ORM::for_table($this->mp2_list_table)->count();
     $total_count += $users_lists_count;
     $result .= sprintf(_n('%d subscribers list', '%d subscribers lists', $users_lists_count, 'mailpoet'), $users_lists_count) . "\n";
 
     // Users
-    $users_count = \ORM::for_table(MP2_USER_TABLE)->count();
+    $users_count = \ORM::for_table($this->mp2_user_table)->count();
     $total_count += $users_count;
     $result .= sprintf(_n('%d subscriber', '%d subscribers', $users_count, 'mailpoet'), $users_count) . "\n";
 
     // Forms
-    $forms_count = \ORM::for_table(MP2_FORM_TABLE)->count();
+    $forms_count = \ORM::for_table($this->mp2_form_table)->count();
     $total_count += $forms_count;
     $result .= sprintf(_n('%d form', '%d forms', $forms_count, 'mailpoet'), $forms_count) . "\n";
 
@@ -337,7 +351,7 @@ class MP2Migrator {
     $lists = array();
 
     $last_id = Setting::getValue('last_imported_list_id', 0);
-    $table = MP2_LIST_TABLE;
+    $table = $this->mp2_list_table;
     $sql = "
       SELECT l.list_id, l.name, l.description, l.is_enabled, l.created_at
       FROM `$table` l
@@ -414,7 +428,7 @@ class MP2Migrator {
     global $wpdb;
     $custom_fields = array();
 
-    $table = MP2_CUSTOM_FIELD_TABLE;
+    $table = $this->mp2_custom_field_table;
     $sql = "
       SELECT cf.id, cf.name, cf.type, cf.required, cf.settings
       FROM `$table` cf
@@ -576,7 +590,7 @@ class MP2Migrator {
     $users = array();
 
     $last_id = Setting::getValue('last_imported_user_id', 0);
-    $table = MP2_USER_TABLE;
+    $table = $this->mp2_user_table;
     $sql = "
       SELECT u.*
       FROM `$table` u
@@ -674,7 +688,7 @@ class MP2Migrator {
     global $wpdb;
     $user_lists = array();
 
-    $table = MP2_USER_LIST_TABLE;
+    $table = $this->mp2_user_list_table;
     $sql = "
       SELECT ul.list_id, ul.sub_date, ul.unsub_date
       FROM `$table` ul
@@ -721,9 +735,7 @@ class MP2Migrator {
     $imported_custom_fields = $this->getImportedCustomFields();
     foreach($imported_custom_fields as $custom_field) {
       $custom_field_column = 'cf_' . $custom_field['id'];
-      if(isset($custom_field_column)) {
-        $this->importSubscriberCustomField($subscriber->id, $custom_field, $user[$custom_field_column]);
-      }
+      $this->importSubscriberCustomField($subscriber->id, $custom_field, $user[$custom_field_column]);
     }
   }
 
@@ -828,7 +840,7 @@ class MP2Migrator {
     $forms = array();
 
     $last_id = Setting::getValue('last_imported_form_id', 0);
-    $table = MP2_FORM_TABLE;
+    $table = $this->mp2_form_table;
     $sql = "
       SELECT f.*
       FROM `$table` f
@@ -962,7 +974,7 @@ class MP2Migrator {
           $segment_id = $this->segments_mapping[$item_value];
           $mp3_value['id'] = $segment_id;
           $segment = Segment::findOne($segment_id);
-          if(isset($segment)) {
+          if($segment) {
             $mp3_value['name'] = $segment->get('name');
           }
         } else {
@@ -1091,7 +1103,7 @@ class MP2Migrator {
     global $wpdb;
     $email = array();
 
-    $table = MP2_EMAIL_TABLE;
+    $table = $this->mp2_email_table;
     $sql = "
       SELECT e.*
       FROM `$table` e
diff --git a/lib/Config/Menu.php b/lib/Config/Menu.php
index c670f294d3..9ee42dae2e 100644
--- a/lib/Config/Menu.php
+++ b/lib/Config/Menu.php
@@ -37,6 +37,8 @@ class Menu {
   const LAST_ANNOUNCEMENT_DATE = '2019-01-28 10:00:00';
 
   public $renderer;
+  public $mp_api_key_valid;
+  public $premium_key_valid;
   private $access_control;
   private $subscribers_over_limit;
   private $wp;
diff --git a/lib/Config/Migrator.php b/lib/Config/Migrator.php
index 2f195f0ec8..fd02fcbbd8 100644
--- a/lib/Config/Migrator.php
+++ b/lib/Config/Migrator.php
@@ -10,6 +10,11 @@ if(!defined('ABSPATH')) exit;
 require_once(ABSPATH . 'wp-admin/includes/upgrade.php');
 
 class Migrator {
+
+  public $prefix;
+  private $charset_collate;
+  private $models;
+
   function __construct() {
     $this->prefix = Env::$db_prefix;
     $this->charset_collate = Env::$db_charset_collate;
diff --git a/lib/Config/PopulatorData/Templates/AppWelcome.php b/lib/Config/PopulatorData/Templates/AppWelcome.php
index 80ffb382a3..589339c10e 100644
--- a/lib/Config/PopulatorData/Templates/AppWelcome.php
+++ b/lib/Config/PopulatorData/Templates/AppWelcome.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class AppWelcome {
 
   private $template_image_url;
@@ -412,4 +413,4 @@ class AppWelcome {
     return $this->template_image_url . '/app-welcome-email.jpg';
   }
 
-}
\ No newline at end of file
+}
diff --git a/lib/Config/PopulatorData/Templates/Avocado.php b/lib/Config/PopulatorData/Templates/Avocado.php
index f0f5a9aa02..0b56997c95 100644
--- a/lib/Config/PopulatorData/Templates/Avocado.php
+++ b/lib/Config/PopulatorData/Templates/Avocado.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class Avocado {
 
   private $template_image_url;
diff --git a/lib/Config/PopulatorData/Templates/BookStoreWithCoupon.php b/lib/Config/PopulatorData/Templates/BookStoreWithCoupon.php
index 43cab0c770..de88b74c68 100644
--- a/lib/Config/PopulatorData/Templates/BookStoreWithCoupon.php
+++ b/lib/Config/PopulatorData/Templates/BookStoreWithCoupon.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class BookStoreWithCoupon {
 
   private $template_image_url;
diff --git a/lib/Config/PopulatorData/Templates/Charity.php b/lib/Config/PopulatorData/Templates/Charity.php
index a5a244f960..66b5f7c2de 100644
--- a/lib/Config/PopulatorData/Templates/Charity.php
+++ b/lib/Config/PopulatorData/Templates/Charity.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class Charity {
 
   private $template_image_url;
diff --git a/lib/Config/PopulatorData/Templates/ClearNews.php b/lib/Config/PopulatorData/Templates/ClearNews.php
index 373420a17e..d09fc7c9bc 100644
--- a/lib/Config/PopulatorData/Templates/ClearNews.php
+++ b/lib/Config/PopulatorData/Templates/ClearNews.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class ClearNews {
 
   private $template_image_url;
diff --git a/lib/Config/PopulatorData/Templates/Coffee.php b/lib/Config/PopulatorData/Templates/Coffee.php
index 33dd486c7f..5b1681b7aa 100644
--- a/lib/Config/PopulatorData/Templates/Coffee.php
+++ b/lib/Config/PopulatorData/Templates/Coffee.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class Coffee {
 
   private $template_image_url;
@@ -999,4 +1000,4 @@ class Coffee {
     );
   }
 
-}
\ No newline at end of file
+}
diff --git a/lib/Config/PopulatorData/Templates/DogFood.php b/lib/Config/PopulatorData/Templates/DogFood.php
index 6a99750ac3..ea09640408 100644
--- a/lib/Config/PopulatorData/Templates/DogFood.php
+++ b/lib/Config/PopulatorData/Templates/DogFood.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class DogFood {
 
   private $template_image_url;
diff --git a/lib/Config/PopulatorData/Templates/Drone.php b/lib/Config/PopulatorData/Templates/Drone.php
index 80e6e5564d..04c9d68871 100644
--- a/lib/Config/PopulatorData/Templates/Drone.php
+++ b/lib/Config/PopulatorData/Templates/Drone.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class Drone {
 
   private $template_image_url;
diff --git a/lib/Config/PopulatorData/Templates/Faith.php b/lib/Config/PopulatorData/Templates/Faith.php
index 024602956a..47412edec1 100644
--- a/lib/Config/PopulatorData/Templates/Faith.php
+++ b/lib/Config/PopulatorData/Templates/Faith.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class Faith {
 
   private $template_image_url;
@@ -9,7 +10,7 @@ class Faith {
 
   function __construct($assets_url) {
      $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/faith';
-    $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
+     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
   function get() {
diff --git a/lib/Config/PopulatorData/Templates/FashionBlogA.php b/lib/Config/PopulatorData/Templates/FashionBlogA.php
index e0c2017dc1..e6b2b196be 100644
--- a/lib/Config/PopulatorData/Templates/FashionBlogA.php
+++ b/lib/Config/PopulatorData/Templates/FashionBlogA.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class FashionBlogA {
 
   private $template_image_url;
diff --git a/lib/Config/PopulatorData/Templates/FashionShop.php b/lib/Config/PopulatorData/Templates/FashionShop.php
index 93aac79ca9..eed3d9aa9c 100644
--- a/lib/Config/PopulatorData/Templates/FashionShop.php
+++ b/lib/Config/PopulatorData/Templates/FashionShop.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class FashionShop {
 
   private $template_image_url;
diff --git a/lib/Config/PopulatorData/Templates/FashionStore.php b/lib/Config/PopulatorData/Templates/FashionStore.php
index 89fda8632e..1509d97989 100644
--- a/lib/Config/PopulatorData/Templates/FashionStore.php
+++ b/lib/Config/PopulatorData/Templates/FashionStore.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class FashionStore {
 
   private $template_image_url;
diff --git a/lib/Config/PopulatorData/Templates/FestivalEvent.php b/lib/Config/PopulatorData/Templates/FestivalEvent.php
index fc9ef57ead..222db84358 100644
--- a/lib/Config/PopulatorData/Templates/FestivalEvent.php
+++ b/lib/Config/PopulatorData/Templates/FestivalEvent.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class FestivalEvent {
 
   private $template_image_url;
@@ -521,4 +522,4 @@ class FestivalEvent {
     return $this->template_image_url . '/festival-event.jpg';
   }
 
-}
\ No newline at end of file
+}
diff --git a/lib/Config/PopulatorData/Templates/Fitness.php b/lib/Config/PopulatorData/Templates/Fitness.php
index 1014338539..fc0c1c4745 100644
--- a/lib/Config/PopulatorData/Templates/Fitness.php
+++ b/lib/Config/PopulatorData/Templates/Fitness.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class Fitness {
 
   private $template_image_url;
diff --git a/lib/Config/PopulatorData/Templates/FlowersWithCoupon.php b/lib/Config/PopulatorData/Templates/FlowersWithCoupon.php
index 3cd5cd1355..085a2aaa10 100644
--- a/lib/Config/PopulatorData/Templates/FlowersWithCoupon.php
+++ b/lib/Config/PopulatorData/Templates/FlowersWithCoupon.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class FlowersWithCoupon {
 
   private $template_image_url;
diff --git a/lib/Config/PopulatorData/Templates/FoodBox.php b/lib/Config/PopulatorData/Templates/FoodBox.php
index 75e3387d7a..6efa2619e3 100644
--- a/lib/Config/PopulatorData/Templates/FoodBox.php
+++ b/lib/Config/PopulatorData/Templates/FoodBox.php
@@ -1,7 +1,7 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
 
 class FoodBox {
 
@@ -754,4 +754,4 @@ class FoodBox {
     return $this->template_image_url . '/welcome-to-foodbox.jpg';
   }
 
-}
\ No newline at end of file
+}
diff --git a/lib/Config/PopulatorData/Templates/GiftWelcome.php b/lib/Config/PopulatorData/Templates/GiftWelcome.php
index b159385c6c..3a8c1a0163 100644
--- a/lib/Config/PopulatorData/Templates/GiftWelcome.php
+++ b/lib/Config/PopulatorData/Templates/GiftWelcome.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class GiftWelcome {
 
   private $template_image_url;
@@ -345,4 +346,4 @@ class GiftWelcome {
   }
 
 
-}
\ No newline at end of file
+}
diff --git a/lib/Config/PopulatorData/Templates/Hotels.php b/lib/Config/PopulatorData/Templates/Hotels.php
index d6ac00f397..f82f548b53 100644
--- a/lib/Config/PopulatorData/Templates/Hotels.php
+++ b/lib/Config/PopulatorData/Templates/Hotels.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class Hotels {
 
   private $template_image_url;
diff --git a/lib/Config/PopulatorData/Templates/IndustryConference.php b/lib/Config/PopulatorData/Templates/IndustryConference.php
index fab587b36e..dca45813f2 100644
--- a/lib/Config/PopulatorData/Templates/IndustryConference.php
+++ b/lib/Config/PopulatorData/Templates/IndustryConference.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class IndustryConference {
 
   private $template_image_url;
diff --git a/lib/Config/PopulatorData/Templates/KidsClothing.php b/lib/Config/PopulatorData/Templates/KidsClothing.php
index f6a38d9eab..b5cab64db0 100644
--- a/lib/Config/PopulatorData/Templates/KidsClothing.php
+++ b/lib/Config/PopulatorData/Templates/KidsClothing.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class KidsClothing {
 
   private $template_image_url;
diff --git a/lib/Config/PopulatorData/Templates/LifestyleBlogA.php b/lib/Config/PopulatorData/Templates/LifestyleBlogA.php
index 4befd00abc..024ad58777 100644
--- a/lib/Config/PopulatorData/Templates/LifestyleBlogA.php
+++ b/lib/Config/PopulatorData/Templates/LifestyleBlogA.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class LifestyleBlogA {
 
   private $template_image_url;
diff --git a/lib/Config/PopulatorData/Templates/LifestyleBlogB.php b/lib/Config/PopulatorData/Templates/LifestyleBlogB.php
index 5be3a2e08f..6453384202 100644
--- a/lib/Config/PopulatorData/Templates/LifestyleBlogB.php
+++ b/lib/Config/PopulatorData/Templates/LifestyleBlogB.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class LifestyleBlogB {
 
   private $template_image_url;
diff --git a/lib/Config/PopulatorData/Templates/Minimal.php b/lib/Config/PopulatorData/Templates/Minimal.php
index 119d19a4d0..5a9ea3987e 100644
--- a/lib/Config/PopulatorData/Templates/Minimal.php
+++ b/lib/Config/PopulatorData/Templates/Minimal.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class Minimal {
 
   private $template_image_url;
diff --git a/lib/Config/PopulatorData/Templates/ModularStyleStories.php b/lib/Config/PopulatorData/Templates/ModularStyleStories.php
index f88f4673fa..bb11698e8f 100644
--- a/lib/Config/PopulatorData/Templates/ModularStyleStories.php
+++ b/lib/Config/PopulatorData/Templates/ModularStyleStories.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class ModularStyleStories {
 
   private $template_image_url;
diff --git a/lib/Config/PopulatorData/Templates/NewsDay.php b/lib/Config/PopulatorData/Templates/NewsDay.php
index 2adeadcad9..c862df7f7f 100644
--- a/lib/Config/PopulatorData/Templates/NewsDay.php
+++ b/lib/Config/PopulatorData/Templates/NewsDay.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class NewsDay {
 
   private $template_image_url;
@@ -9,7 +10,7 @@ class NewsDay {
 
   function __construct($assets_url) {
      $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/news_day';
-    $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
+     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
   function get() {
diff --git a/lib/Config/PopulatorData/Templates/NewsletterBlank121Column.php b/lib/Config/PopulatorData/Templates/NewsletterBlank121Column.php
index e749d4a0b5..f264a70132 100644
--- a/lib/Config/PopulatorData/Templates/NewsletterBlank121Column.php
+++ b/lib/Config/PopulatorData/Templates/NewsletterBlank121Column.php
@@ -5,6 +5,11 @@ if(!defined('ABSPATH')) exit;
 
 class NewsletterBlank121Column {
 
+  private $assets_url;
+  private $external_template_image_url;
+  private $template_image_url;
+  private $social_icon_url;
+
   function __construct($assets_url) {
     $this->assets_url = $assets_url;
     $this->external_template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/newsletter-blank-1-2-1-column';
diff --git a/lib/Config/PopulatorData/Templates/NewsletterBlank12Column.php b/lib/Config/PopulatorData/Templates/NewsletterBlank12Column.php
index d80aa56e0d..65b9a58684 100644
--- a/lib/Config/PopulatorData/Templates/NewsletterBlank12Column.php
+++ b/lib/Config/PopulatorData/Templates/NewsletterBlank12Column.php
@@ -5,6 +5,11 @@ if(!defined('ABSPATH')) exit;
 
 class NewsletterBlank12Column {
 
+  private $assets_url;
+  private $external_template_image_url;
+  private $template_image_url;
+  private $social_icon_url;
+
   function __construct($assets_url) {
     $this->assets_url = $assets_url;
     $this->external_template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/newsletter-blank-1-2-column';
diff --git a/lib/Config/PopulatorData/Templates/NewsletterBlank13Column.php b/lib/Config/PopulatorData/Templates/NewsletterBlank13Column.php
index 1420fb0998..62a91c4e59 100644
--- a/lib/Config/PopulatorData/Templates/NewsletterBlank13Column.php
+++ b/lib/Config/PopulatorData/Templates/NewsletterBlank13Column.php
@@ -5,6 +5,11 @@ if(!defined('ABSPATH')) exit;
 
 class NewsletterBlank13Column {
 
+  private $assets_url;
+  private $external_template_image_url;
+  private $template_image_url;
+  private $social_icon_url;
+
   function __construct($assets_url) {
     $this->assets_url = $assets_url;
     $this->external_template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/newsletter-blank-1-3-column';
diff --git a/lib/Config/PopulatorData/Templates/NewsletterBlank1Column.php b/lib/Config/PopulatorData/Templates/NewsletterBlank1Column.php
index 64ae6a92a4..9ed9e20f8b 100644
--- a/lib/Config/PopulatorData/Templates/NewsletterBlank1Column.php
+++ b/lib/Config/PopulatorData/Templates/NewsletterBlank1Column.php
@@ -5,6 +5,11 @@ if(!defined('ABSPATH')) exit;
 
 class NewsletterBlank1Column {
 
+  private $assets_url;
+  private $external_template_image_url;
+  private $template_image_url;
+  private $social_icon_url;
+
   function __construct($assets_url) {
     $this->assets_url = $assets_url;
     $this->external_template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/newsletter-blank-1-column';
diff --git a/lib/Config/PopulatorData/Templates/NewspaperTraditional.php b/lib/Config/PopulatorData/Templates/NewspaperTraditional.php
index 131cb3b7e4..b2a4267741 100644
--- a/lib/Config/PopulatorData/Templates/NewspaperTraditional.php
+++ b/lib/Config/PopulatorData/Templates/NewspaperTraditional.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class NewspaperTraditional {
 
   private $template_image_url;
diff --git a/lib/Config/PopulatorData/Templates/NotSoMedium.php b/lib/Config/PopulatorData/Templates/NotSoMedium.php
index 56cd7560c3..b327f6b3d9 100644
--- a/lib/Config/PopulatorData/Templates/NotSoMedium.php
+++ b/lib/Config/PopulatorData/Templates/NotSoMedium.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class NotSoMedium {
 
   private $template_image_url;
diff --git a/lib/Config/PopulatorData/Templates/Phone.php b/lib/Config/PopulatorData/Templates/Phone.php
index cf8c4da367..8d9c9534da 100644
--- a/lib/Config/PopulatorData/Templates/Phone.php
+++ b/lib/Config/PopulatorData/Templates/Phone.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class Phone {
 
   private $template_image_url;
diff --git a/lib/Config/PopulatorData/Templates/PieceOfCake.php b/lib/Config/PopulatorData/Templates/PieceOfCake.php
index 33b1d15fdb..5809acac95 100644
--- a/lib/Config/PopulatorData/Templates/PieceOfCake.php
+++ b/lib/Config/PopulatorData/Templates/PieceOfCake.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class PieceOfCake {
 
   private $template_image_url;
@@ -441,4 +442,4 @@ class PieceOfCake {
     return $this->template_image_url . '/piece-of-cake.jpg';
   }
 
-}
\ No newline at end of file
+}
diff --git a/lib/Config/PopulatorData/Templates/PostNotificationsBlank1Column.php b/lib/Config/PopulatorData/Templates/PostNotificationsBlank1Column.php
index a8852594bc..975dcb3ddd 100644
--- a/lib/Config/PopulatorData/Templates/PostNotificationsBlank1Column.php
+++ b/lib/Config/PopulatorData/Templates/PostNotificationsBlank1Column.php
@@ -5,6 +5,11 @@ if(!defined('ABSPATH')) exit;
 
 class PostNotificationsBlank1Column {
 
+  private $assets_url;
+  private $external_template_image_url;
+  private $template_image_url;
+  private $social_icon_url;
+
   function __construct($assets_url) {
     $this->assets_url = $assets_url;
     $this->external_template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/post-notifications-blank-1-column';
diff --git a/lib/Config/PopulatorData/Templates/Retro.php b/lib/Config/PopulatorData/Templates/Retro.php
index 0b4b913652..5d6c777a24 100644
--- a/lib/Config/PopulatorData/Templates/Retro.php
+++ b/lib/Config/PopulatorData/Templates/Retro.php
@@ -1,7 +1,8 @@
 <?php
-
 namespace MailPoet\Config\PopulatorData\Templates;
 
+if(!defined('ABSPATH')) exit;
+
 class Retro {
 
   private $template_image_url;
diff --git a/lib/Config/PopulatorData/Templates/ScienceWeekly.php b/lib/Config/PopulatorData/Templates/ScienceWeekly.php
index 5d3f6c4352..2b052d9122 100644
--- a/lib/Config/PopulatorData/Templates/ScienceWeekly.php
+++ b/lib/Config/PopulatorData/Templates/ScienceWeekly.php
@@ -9,7 +9,7 @@ class ScienceWeekly {
 
   function __construct($assets_url) {
      $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/science_weekly';
-    $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
+     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
   function get() {
diff --git a/lib/Config/PopulatorData/Templates/Shoes.php b/lib/Config/PopulatorData/Templates/Shoes.php
index 543e61a43d..5464023b61 100644
--- a/lib/Config/PopulatorData/Templates/Shoes.php
+++ b/lib/Config/PopulatorData/Templates/Shoes.php
@@ -9,7 +9,7 @@ class Shoes {
 
   function __construct($assets_url) {
      $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/shoes';
-    $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
+     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
   function get() {
@@ -576,4 +576,4 @@ class Shoes {
     return $this->template_image_url . '/shoes.jpg';
   }
 
-}
\ No newline at end of file
+}
diff --git a/lib/Config/PopulatorData/Templates/SimpleText.php b/lib/Config/PopulatorData/Templates/SimpleText.php
index 3b24c70692..b6eaad5087 100644
--- a/lib/Config/PopulatorData/Templates/SimpleText.php
+++ b/lib/Config/PopulatorData/Templates/SimpleText.php
@@ -5,6 +5,11 @@ if(!defined('ABSPATH')) exit;
 
 class SimpleText {
 
+  private $assets_url;
+  private $external_template_image_url;
+  private $template_image_url;
+  private $social_icon_url;
+
   function __construct($assets_url) {
     $this->assets_url = $assets_url;
     $this->external_template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/simple-text';
diff --git a/lib/Config/PopulatorData/Templates/Sunglasses.php b/lib/Config/PopulatorData/Templates/Sunglasses.php
index 4400c064de..7d8b653574 100644
--- a/lib/Config/PopulatorData/Templates/Sunglasses.php
+++ b/lib/Config/PopulatorData/Templates/Sunglasses.php
@@ -2,7 +2,6 @@
 
 namespace MailPoet\Config\PopulatorData\Templates;
 
-
 class Sunglasses {
 
   private $template_image_url;
diff --git a/lib/Config/PopulatorData/Templates/TakeAHike.php b/lib/Config/PopulatorData/Templates/TakeAHike.php
index fa9e1079bb..0c7f1f6056 100644
--- a/lib/Config/PopulatorData/Templates/TakeAHike.php
+++ b/lib/Config/PopulatorData/Templates/TakeAHike.php
@@ -9,7 +9,7 @@ class TakeAHike {
 
   function __construct($assets_url) {
      $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/take_a_hike';
-    $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
+     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
   function get() {
diff --git a/lib/Config/PopulatorData/Templates/WelcomeBlank12Column.php b/lib/Config/PopulatorData/Templates/WelcomeBlank12Column.php
index 0eb444102b..e1bdce000f 100644
--- a/lib/Config/PopulatorData/Templates/WelcomeBlank12Column.php
+++ b/lib/Config/PopulatorData/Templates/WelcomeBlank12Column.php
@@ -5,6 +5,11 @@ if(!defined('ABSPATH')) exit;
 
 class WelcomeBlank12Column {
 
+  private $assets_url;
+  private $external_template_image_url;
+  private $template_image_url;
+  private $social_icon_url;
+
   function __construct($assets_url) {
     $this->assets_url = $assets_url;
     $this->external_template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/welcome-email-blank-1-2-column';
diff --git a/lib/Config/PopulatorData/Templates/WelcomeBlank1Column.php b/lib/Config/PopulatorData/Templates/WelcomeBlank1Column.php
index 1ad3124f7f..e454c8dfe7 100644
--- a/lib/Config/PopulatorData/Templates/WelcomeBlank1Column.php
+++ b/lib/Config/PopulatorData/Templates/WelcomeBlank1Column.php
@@ -5,6 +5,11 @@ if(!defined('ABSPATH')) exit;
 
 class WelcomeBlank1Column {
 
+  private $assets_url;
+  private $external_template_image_url;
+  private $template_image_url;
+  private $social_icon_url;
+
   function __construct($assets_url) {
     $this->assets_url = $assets_url;
     $this->external_template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/welcome-email-blank-1-column';
diff --git a/lib/Cron/Workers/SendingQueue/Migration.php b/lib/Cron/Workers/SendingQueue/Migration.php
index 657debea80..38fda2a5dc 100644
--- a/lib/Cron/Workers/SendingQueue/Migration.php
+++ b/lib/Cron/Workers/SendingQueue/Migration.php
@@ -24,6 +24,9 @@ class Migration extends SimpleWorker {
 
   function prepareTask(ScheduledTask $task) {
     $unmigrated_columns = self::checkUnmigratedColumnsExist();
+    $unmigrated_queues_count = 0;
+    $unmigrated_queue_subscribers = [];
+
     if($unmigrated_columns) {
       $unmigrated_queues_count = $this->getUnmigratedQueues()->count();
       $unmigrated_queue_subscribers = $this->getTaskIdsForUnmigratedSubscribers();
diff --git a/lib/Cron/Workers/SendingQueue/SendingQueue.php b/lib/Cron/Workers/SendingQueue/SendingQueue.php
index f01bf4197a..dc49b1db0a 100644
--- a/lib/Cron/Workers/SendingQueue/SendingQueue.php
+++ b/lib/Cron/Workers/SendingQueue/SendingQueue.php
@@ -22,6 +22,7 @@ class SendingQueue {
   public $mailer_task;
   public $newsletter_task;
   public $timer;
+  public $batch_size;
   const BATCH_SIZE = 20;
   const TASK_BATCH_SIZE = 5;
 
diff --git a/lib/DI/ContainerWrapper.php b/lib/DI/ContainerWrapper.php
index a4af0e8d88..7be76c373b 100644
--- a/lib/DI/ContainerWrapper.php
+++ b/lib/DI/ContainerWrapper.php
@@ -61,7 +61,7 @@ class ContainerWrapper implements ContainerInterface {
   }
 
   private static function createPremiumContainer(ContainerInterface $free_container, $debug = false) {
-    $premium_container_factory =  new ContainerFactory(new \MailPoet\Premium\DI\ContainerConfigurator($free_container), $debug);
+    $premium_container_factory =  new ContainerFactory(new \MailPoet\Premium\DI\ContainerConfigurator(), $debug);
     $premium_container = $premium_container_factory->getContainer();
     $premium_container->set(IContainerConfigurator::FREE_CONTAINER_SERVICE_SLUG, $free_container);
     $free_container->set(IContainerConfigurator::PREMIUM_CONTAINER_SERVICE_SLUG, $premium_container);
diff --git a/lib/Form/Block/Html.php b/lib/Form/Block/Html.php
index 3fc2b75eac..c13b892d6c 100644
--- a/lib/Form/Block/Html.php
+++ b/lib/Form/Block/Html.php
@@ -5,6 +5,7 @@ class Html {
 
   static function render($block) {
     $html = '';
+    $text = '';
 
     if(isset($block['params']['text']) && $block['params']['text']) {
       $text = html_entity_decode($block['params']['text'], ENT_QUOTES);
diff --git a/lib/Form/Util/Styles.php b/lib/Form/Util/Styles.php
index 372466303e..114039ae9b 100644
--- a/lib/Form/Util/Styles.php
+++ b/lib/Form/Util/Styles.php
@@ -78,6 +78,7 @@ class Styles {
   background-color: #5b5b5b;
 }
 EOL;
+  private $stylesheet;
 
   function __construct($stylesheet = null) {
     $this->stylesheet = $stylesheet;
diff --git a/lib/Mailer/Methods/SMTP.php b/lib/Mailer/Methods/SMTP.php
index fc5e2e5dae..f851c97824 100644
--- a/lib/Mailer/Methods/SMTP.php
+++ b/lib/Mailer/Methods/SMTP.php
@@ -18,6 +18,7 @@ class SMTP {
   public $reply_to;
   public $return_path;
   public $mailer;
+  private $mailer_logger;
   const SMTP_CONNECTION_TIMEOUT = 15; // seconds
 
   /** @var SMTPMapper */
diff --git a/lib/Models/CustomField.php b/lib/Models/CustomField.php
index bcad797b4d..36d8445aca 100644
--- a/lib/Models/CustomField.php
+++ b/lib/Models/CustomField.php
@@ -5,6 +5,10 @@ use MailPoet\Form\Block\Date;
 
 if(!defined('ABSPATH')) exit;
 
+/**
+ * @property string $type
+ * @property string|array $params
+ */
 class CustomField extends Model {
   public static $_table = MP_CUSTOM_FIELDS_TABLE;
   const TYPE_DATE = 'date';
diff --git a/lib/Models/Form.php b/lib/Models/Form.php
index 54dc8995e2..639865091e 100644
--- a/lib/Models/Form.php
+++ b/lib/Models/Form.php
@@ -3,6 +3,10 @@ namespace MailPoet\Models;
 
 if(!defined('ABSPATH')) exit;
 
+/**
+ * @property string|array $settings
+ * @property string|array $body
+ */
 class Form extends Model {
   public static $_table = MP_FORMS_TABLE;
 
diff --git a/lib/Models/Model.php b/lib/Models/Model.php
index c388889734..4de13f7211 100644
--- a/lib/Models/Model.php
+++ b/lib/Models/Model.php
@@ -19,26 +19,40 @@ if(!defined('ABSPATH')) exit;
  * @method array getConnectionNames()
  * @method $this useIdColumn($id_column)
  * @method \ORM|bool findOne($id=null)
+ * @method static \ORM|bool findOne($id=null)
  * @method array|\IdiormResultSet findMany()
+ * @method static array|\IdiormResultSet findMany()
  * @method \IdiormResultSet findResultSet()
  * @method array findArray()
+ * @method static array findArray()
  * @method $this forceAllDirty()
  * @method $this rawQuery($query, $parameters = array())
+ * @method static $this rawQuery($query, $parameters = array())
  * @method $this tableAlias($alias)
+ * @method static $this tableAlias($alias)
  * @method int countNullIdColumns()
+ * @method $this select($column, $alias=null)
+ * @method static $this select($column, $alias=null)
  * @method $this selectExpr($expr, $alias=null)
- * @method \ORM selectMany($values)
+ * @method static $this selectExpr($expr, $alias=null)
+ * @method \ORM selectMany(...$values)
+ * @method static \ORM selectMany(...$values)
  * @method \ORM selectManyExpr($values)
  * @method $this rawJoin($table, $constraint, $table_alias, $parameters = array())
  * @method $this innerJoin($table, $constraint, $table_alias=null)
  * @method $this leftOuterJoin($table, $constraint, $table_alias=null)
  * @method $this rightOuterJoin($table, $constraint, $table_alias=null)
  * @method $this fullOuterJoin($table, $constraint, $table_alias=null)
+ * @method $this where($column_name, $value=null)
+ * @method static $this where($column_name, $value=null)
  * @method $this whereEqual($column_name, $value=null)
+ * @method static $this whereEqual($column_name, $value=null)
  * @method $this whereNotEqual($column_name, $value=null)
+ * @method static $this whereNotEqual($column_name, $value=null)
  * @method $this whereIdIs($id)
  * @method $this whereAnyIs($values, $operator='=')
  * @method array|string whereIdIn($ids)
+ * @method static array|string whereIdIn($ids)
  * @method $this whereLike($column_name, $value=null)
  * @method $this whereNotLike($column_name, $value=null)
  * @method $this whereGt($column_name, $value=null)
@@ -46,13 +60,19 @@ if(!defined('ABSPATH')) exit;
  * @method $this whereGte($column_name, $value=null)
  * @method $this whereLte($column_name, $value=null)
  * @method $this whereIn($column_name, $values)
+ * @method static $this whereIn($column_name, $values)
  * @method $this whereNotIn($column_name, $values)
  * @method $this whereNull($column_name)
+ * @method static $this whereNull($column_name)
  * @method $this whereNotNull($column_name)
+ * @method static $this whereNotNull($column_name)
  * @method $this whereRaw($clause, $parameters=array())
+ * @method static $this whereRaw($clause, $parameters=array())
  * @method $this deleteMany()
  * @method $this orderByDesc($column_name)
+ * @method static $this orderByDesc($column_name)
  * @method $this orderByAsc($column_name)
+ * @method static $this orderByAsc($column_name)
  * @method $this orderByExpr($clause)
  * @method $this groupBy($column_name)
  * @method $this groupByExpr($expr)
@@ -73,10 +93,21 @@ if(!defined('ABSPATH')) exit;
  * @method static $this clearCache($table_name = null, $connection_name = self::DEFAULT_CONNECTION)
  * @method bool setExpr($key, $value = null)
  * @method bool isDirty($key)
+ * @method static ORMWrapper filter(...$args)
+ * @method \ORMWrapper hasMany($associated_class_name, $foreign_key_name=null, $foreign_key_name_in_current_models_table=null, $connection_name=null)
+ * @method \ORMWrapper hasManyThrough($associated_class_name, $join_class_name=null, $key_to_base_table=null, $key_to_associated_table=null,  $key_in_base_table=null, $key_in_associated_table=null, $connection_name=null)
+ * @method \ORMWrapper hasOne($associated_class_name, $foreign_key_name=null, $foreign_key_name_in_current_models_table=null, $connection_name=null)
+ * @method \ORMWrapper|bool create($data=null)
+ * @method static \ORMWrapper|bool create($data=null)
+ * @method int count()
+ * @method static int count()
+ *
+ * @property string|null $created_at
  */
 class Model extends \Sudzy\ValidModel {
   const DUPLICATE_RECORD = 23000;
 
+  public static $_table;
   protected $_errors;
   protected $_new_record;
 
@@ -311,4 +342,4 @@ class Model extends \Sudzy\ValidModel {
     $this->setError($this->getValidationErrors());
     return $success;
   }
-}
\ No newline at end of file
+}
diff --git a/lib/Models/Newsletter.php b/lib/Models/Newsletter.php
index ab771de381..191e444915 100644
--- a/lib/Models/Newsletter.php
+++ b/lib/Models/Newsletter.php
@@ -10,6 +10,22 @@ use function MailPoet\Util\array_column;
 
 if(!defined('ABSPATH')) exit;
 
+/**
+ * @property int $id
+ * @property string $type
+ * @property object $queue
+ * @property string $hash
+ * @property string $status
+ * @property string|object $meta
+ * @property array $options
+ * @property int $children_count
+ * @property bool|array $statistics
+ * @property string $deleted_at
+ * @property int $children_count
+ * @property int $total_sent
+ * @property int $total_scheduled
+ * @property array $segments
+ */
 class Newsletter extends Model {
   public static $_table = MP_NEWSLETTERS_TABLE;
   const TYPE_AUTOMATIC = 'automatic';
@@ -601,7 +617,7 @@ class Newsletter extends Model {
   }
 
   static function sentAfter($date) {
-    return static::table_alias('newsletters')
+    return static::tableAlias('newsletters')
       ->where('newsletters.type', self::TYPE_STANDARD)
       ->where('newsletters.status', self::STATUS_SENT)
       ->join(
@@ -951,7 +967,7 @@ class Newsletter extends Model {
   }
 
   static function getWelcomeNotificationsForSegments($segments) {
-    return NewsletterOption::table_alias('options')
+    return NewsletterOption::tableAlias('options')
       ->select('options.newsletter_id')
       ->select('options.value', 'segment_id')
       ->join(
@@ -972,7 +988,7 @@ class Newsletter extends Model {
   }
 
   static function getArchives($segment_ids = array()) {
-    $orm = self::table_alias('newsletters')
+    $orm = self::tableAlias('newsletters')
       ->distinct()->select('newsletters.*')
       ->select('newsletter_rendered_subject')
       ->whereIn('newsletters.type', array(
diff --git a/lib/Models/ScheduledTask.php b/lib/Models/ScheduledTask.php
index 5b6cffcea9..9cdb71e0c6 100644
--- a/lib/Models/ScheduledTask.php
+++ b/lib/Models/ScheduledTask.php
@@ -6,6 +6,11 @@ use MailPoet\WP\Functions as WPFunctions;
 
 if(!defined('ABSPATH')) exit;
 
+/**
+ * @property int $id
+ * @property string $processed_at
+ * @property int $priority
+ */
 class ScheduledTask extends Model {
   public static $_table = MP_SCHEDULED_TASKS_TABLE;
   const STATUS_COMPLETED = 'completed';
diff --git a/lib/Models/Segment.php b/lib/Models/Segment.php
index bc8a7feb8c..d553e6621e 100644
--- a/lib/Models/Segment.php
+++ b/lib/Models/Segment.php
@@ -3,6 +3,10 @@ namespace MailPoet\Models;
 
 if(!defined('ABSPATH')) exit;
 
+/**
+ * @property int $id
+ * @property array $subscribers_count
+ */
 class Segment extends Model {
   static $_table = MP_SEGMENTS_TABLE;
   const TYPE_WP_USERS = 'wp_users';
@@ -71,7 +75,7 @@ class Segment extends Model {
   }
 
   function withSubscribersCount() {
-    $this->subscribers_count = SubscriberSegment::table_alias('relation')
+    $this->subscribers_count = SubscriberSegment::tableAlias('relation')
       ->where('relation.segment_id', $this->id)
       ->join(
         MP_SUBSCRIBERS_TABLE,
@@ -208,7 +212,7 @@ class Segment extends Model {
   }
 
   static function getSegmentsForExport() {
-    return self::raw_query(
+    return self::rawQuery(
       '(SELECT segments.id, segments.name, COUNT(relation.subscriber_id) as subscribers ' .
       'FROM ' . MP_SUBSCRIBER_SEGMENT_TABLE . ' relation ' .
       'LEFT JOIN ' . self::$_table . ' segments ON segments.id = relation.segment_id ' .
@@ -271,7 +275,7 @@ class Segment extends Model {
   }
 
   static function getAnalytics() {
-    $analytics = Segment::select_expr('type, count(*) as count')
+    $analytics = Segment::selectExpr('type, count(*) as count')
                         ->whereNull('deleted_at')
                         ->groupBy('type')
                         ->findArray();
diff --git a/lib/Models/SendingQueue.php b/lib/Models/SendingQueue.php
index f443aaeb73..8680202d1c 100644
--- a/lib/Models/SendingQueue.php
+++ b/lib/Models/SendingQueue.php
@@ -7,6 +7,14 @@ use MailPoet\Tasks\Subscribers as TaskSubscribers;
 
 if(!defined('ABSPATH')) exit;
 
+/**
+ * @property int $count_processed
+ * @property int $count_total
+ * @property string $newsletter_rendered_body
+ * @property int $task_id
+ * @property string|object $meta
+ * @property string|array $subscribers
+ */
 class SendingQueue extends Model {
   public static $_table = MP_SENDING_QUEUES_TABLE;
   const STATUS_COMPLETED = 'completed';
@@ -151,7 +159,7 @@ class SendingQueue extends Model {
   }
 
   static function getTasks() {
-    return ScheduledTask::table_alias('tasks')
+    return ScheduledTask::tableAlias('tasks')
     ->selectExpr('tasks.*')
     ->join(
       MP_SENDING_QUEUES_TABLE,
@@ -161,7 +169,7 @@ class SendingQueue extends Model {
   }
 
   static function joinWithTasks() {
-    return static::table_alias('queues')
+    return static::tableAlias('queues')
     ->join(
       MP_SCHEDULED_TASKS_TABLE,
       'tasks.id = queues.task_id',
diff --git a/lib/Models/StatisticsClicks.php b/lib/Models/StatisticsClicks.php
index 6beb47443b..8e874d7d23 100644
--- a/lib/Models/StatisticsClicks.php
+++ b/lib/Models/StatisticsClicks.php
@@ -26,7 +26,7 @@ class StatisticsClicks extends Model {
   }
 
   static function getAllForSubscriber(Subscriber $subscriber) {
-    return static::table_alias('clicks')
+    return static::tableAlias('clicks')
       ->select('clicks.id', 'id')
       ->select('newsletter_rendered_subject')
       ->select('clicks.created_at', 'created_at')
diff --git a/lib/Models/StatisticsNewsletters.php b/lib/Models/StatisticsNewsletters.php
index d332ea35e8..182f62766b 100644
--- a/lib/Models/StatisticsNewsletters.php
+++ b/lib/Models/StatisticsNewsletters.php
@@ -31,7 +31,7 @@ class StatisticsNewsletters extends Model {
   }
 
   static function getAllForSubscriber(Subscriber $subscriber) {
-    return static::table_alias('statistics')
+    return static::tableAlias('statistics')
       ->select('statistics.newsletter_id', 'newsletter_id')
       ->select('newsletter_rendered_subject')
       ->select('opens.created_at', 'opened_at')
diff --git a/lib/Models/Subscriber.php b/lib/Models/Subscriber.php
index 1126a26a62..54f6ae3841 100644
--- a/lib/Models/Subscriber.php
+++ b/lib/Models/Subscriber.php
@@ -10,6 +10,14 @@ use function MailPoet\Util\array_column;
 
 if(!defined('ABSPATH')) exit;
 
+/**
+ * @property int $id
+ * @property string $email
+ * @property int $wp_user_id
+ * @property array $segments
+ * @property array $subscriptions
+ * @property string $unconfirmed_data
+ */
 class Subscriber extends Model {
   public static $_table = MP_SUBSCRIBERS_TABLE;
 
@@ -378,7 +386,7 @@ class Subscriber extends Model {
   }
 
   static function getSubscribedInSegments($segment_ids) {
-    $subscribers = SubscriberSegment::table_alias('relation')
+    $subscribers = SubscriberSegment::tableAlias('relation')
       ->whereIn('relation.segment_id', $segment_ids)
       ->where('relation.status', 'subscribed')
       ->join(
@@ -518,7 +526,7 @@ class Subscriber extends Model {
     $custom_field_ids = array_keys($custom_fields_data);
 
     // get custom fields
-    $custom_fields = CustomField::findMany($custom_field_ids);
+    $custom_fields = CustomField::whereIdIn($custom_field_ids)->findMany();
 
     foreach($custom_fields as $custom_field) {
       $value = (isset($custom_fields_data[$custom_field->id])
@@ -838,7 +846,7 @@ class Subscriber extends Model {
   }
 
   public function getAllSegmentNamesWithStatus() {
-    return Segment::table_alias('segment')
+    return Segment::tableAlias('segment')
       ->select('name')
       ->select('subscriber_segment.segment_id', 'segment_id')
       ->select('subscriber_segment.status', 'status')
diff --git a/lib/Newsletter/Editor/PostListTransformer.php b/lib/Newsletter/Editor/PostListTransformer.php
index 622905e00f..bad9f3696f 100644
--- a/lib/Newsletter/Editor/PostListTransformer.php
+++ b/lib/Newsletter/Editor/PostListTransformer.php
@@ -7,6 +7,9 @@ if(!defined('ABSPATH')) exit;
 
 class PostListTransformer {
 
+  private $args;
+  private $transformer;
+
   function __construct($args) {
     $this->args = $args;
     $this->transformer = new PostTransformer($args);
diff --git a/lib/Newsletter/Editor/TitleListTransformer.php b/lib/Newsletter/Editor/TitleListTransformer.php
index fbec65b2c2..10d9a854f8 100644
--- a/lib/Newsletter/Editor/TitleListTransformer.php
+++ b/lib/Newsletter/Editor/TitleListTransformer.php
@@ -5,6 +5,8 @@ if(!defined('ABSPATH')) exit;
 
 class TitleListTransformer {
 
+  private $args;
+
   function __construct($args) {
     $this->args = $args;
   }
diff --git a/lib/Newsletter/Editor/Transformer.php b/lib/Newsletter/Editor/Transformer.php
index b2df6cf989..8bb8c0e638 100644
--- a/lib/Newsletter/Editor/Transformer.php
+++ b/lib/Newsletter/Editor/Transformer.php
@@ -8,6 +8,8 @@ if(!defined('ABSPATH')) exit;
 
 class Transformer {
 
+  private $transformer;
+
   function __construct($args) {
     $title_list_only = $args['displayType'] === 'titleOnly' && $args['titleFormat'] === 'ul';
 
diff --git a/lib/Newsletter/Renderer/Renderer.php b/lib/Newsletter/Renderer/Renderer.php
index 3fc8f3118f..4e743cac8b 100644
--- a/lib/Newsletter/Renderer/Renderer.php
+++ b/lib/Newsletter/Renderer/Renderer.php
@@ -15,6 +15,9 @@ class Renderer {
   public $CSS_inliner;
   public $newsletter;
   public $preview;
+  public $premium_activated;
+  public $mss_activated;
+  private $template;
   const NEWSLETTER_TEMPLATE = 'Template.html';
   const FILTER_POST_PROCESS = 'mailpoet_rendering_post_process';
 
diff --git a/lib/Newsletter/Scheduler/Scheduler.php b/lib/Newsletter/Scheduler/Scheduler.php
index 81b72a5b93..5be6366c1d 100644
--- a/lib/Newsletter/Scheduler/Scheduler.php
+++ b/lib/Newsletter/Scheduler/Scheduler.php
@@ -147,7 +147,7 @@ class Scheduler {
   }
 
   static function createPostNotificationSendingTask($newsletter) {
-    $existing_notification_history = Newsletter::table_alias('newsletters')
+    $existing_notification_history = Newsletter::tableAlias('newsletters')
       ->where('newsletters.parent_id', $newsletter->id)
       ->where('newsletters.type', Newsletter::TYPE_NOTIFICATION_HISTORY)
       ->where('newsletters.status', Newsletter::STATUS_SENDING)
@@ -194,9 +194,6 @@ class Scheduler {
       $newsletter->nthWeekDay :
       '#' . $newsletter->nthWeekDay;
     switch($interval_type) {
-      case self::INTERVAL_IMMEDIATELY:
-        $schedule = '* * * * *';
-        break;
       case self::INTERVAL_IMMEDIATE:
       case self::INTERVAL_DAILY:
         $schedule = sprintf('0 %s * * *', $hour);
@@ -210,6 +207,10 @@ class Scheduler {
       case self::INTERVAL_MONTHLY:
         $schedule = sprintf('0 %s %s * *', $hour, $month_day);
         break;
+      case self::INTERVAL_IMMEDIATELY:
+      default:
+        $schedule = '* * * * *';
+        break;
     }
     $option_field = NewsletterOptionField::where('name', 'schedule')->findOne();
     $relation = NewsletterOption::where('newsletter_id', $newsletter->id)
diff --git a/lib/Router/Endpoints/ViewInBrowser.php b/lib/Router/Endpoints/ViewInBrowser.php
index a6d42cd462..b15d297b06 100644
--- a/lib/Router/Endpoints/ViewInBrowser.php
+++ b/lib/Router/Endpoints/ViewInBrowser.php
@@ -18,6 +18,7 @@ class ViewInBrowser {
   public $permissions = array(
     'global' => AccessControl::NO_ACCESS_RESTRICTION
   );
+  private $access_control;
 
   function __construct(AccessControl $access_control) {
     $this->access_control = $access_control;
diff --git a/lib/Router/Router.php b/lib/Router/Router.php
index 7b5e041a17..99d123faea 100644
--- a/lib/Router/Router.php
+++ b/lib/Router/Router.php
@@ -13,6 +13,8 @@ class Router {
   public $endpoint;
   public $action;
   public $data;
+  public $endpoint_action;
+  public $access_control;
   /** @var ContainerInterface */
   private $container;
   const NAME = 'mailpoet_router';
diff --git a/lib/Segments/SubscribersFinder.php b/lib/Segments/SubscribersFinder.php
index 2ffce4bd0d..3c9f51250f 100644
--- a/lib/Segments/SubscribersFinder.php
+++ b/lib/Segments/SubscribersFinder.php
@@ -14,7 +14,7 @@ class SubscribersFinder {
   function findSubscribersInSegments($subscribers_to_process_ids, $newsletter_segments_ids) {
     $result = array();
     foreach($newsletter_segments_ids as $segment_id) {
-      $segment = Segment::find_one($segment_id);
+      $segment = Segment::findOne($segment_id);
       $result = array_merge($result, $this->findSubscribersInSegment($segment, $subscribers_to_process_ids));
     }
     return $this->unique($result);
diff --git a/lib/Segments/WP.php b/lib/Segments/WP.php
index 0ccb4bd4d8..872d6187c4 100644
--- a/lib/Segments/WP.php
+++ b/lib/Segments/WP.php
@@ -111,11 +111,11 @@ class WP {
 
   private static function updateSubscribersEmails() {
     global $wpdb;
-    Subscriber::raw_execute('SELECT NOW();');
-    $start_time = Subscriber::get_last_statement()->fetch(\PDO::FETCH_COLUMN);
+    Subscriber::rawExecute('SELECT NOW();');
+    $start_time = Subscriber::getLastStatement()->fetch(\PDO::FETCH_COLUMN);
 
     $subscribers_table = Subscriber::$_table;
-    Subscriber::raw_execute(sprintf('
+    Subscriber::rawExecute(sprintf('
       UPDATE IGNORE %1$s
         INNER JOIN %2$s as wu ON %1$s.wp_user_id = wu.id
       SET %1$s.email = wu.user_email;
@@ -137,7 +137,7 @@ class WP {
         WHERE mps.wp_user_id IS NULL AND %2$s.user_email != ""
       ', $subscribers_table, $wpdb->users))->findArray();
 
-    Subscriber::raw_execute(sprintf('
+    Subscriber::rawExecute(sprintf('
       INSERT IGNORE INTO %1$s(wp_user_id, email, status, created_at, source)
         SELECT wu.id, wu.user_email, "subscribed", CURRENT_TIMESTAMP(), "%3$s" FROM %2$s wu
           LEFT JOIN %1$s mps ON wu.id = mps.wp_user_id
@@ -151,7 +151,7 @@ class WP {
   private static function updateFirstNames() {
     global $wpdb;
     $subscribers_table = Subscriber::$_table;
-    Subscriber::raw_execute(sprintf('
+    Subscriber::rawExecute(sprintf('
       UPDATE %1$s
         JOIN %2$s as wpum ON %1$s.wp_user_id = wpum.user_id AND wpum.meta_key = "first_name"
       SET %1$s.first_name = wpum.meta_value
@@ -164,7 +164,7 @@ class WP {
   private static function updateLastNames() {
     global $wpdb;
     $subscribers_table = Subscriber::$_table;
-    Subscriber::raw_execute(sprintf('
+    Subscriber::rawExecute(sprintf('
       UPDATE %1$s
         JOIN %2$s as wpum ON %1$s.wp_user_id = wpum.user_id AND wpum.meta_key = "last_name"
       SET %1$s.last_name = wpum.meta_value
@@ -177,7 +177,7 @@ class WP {
   private static function updateFirstNameIfMissing() {
     global $wpdb;
     $subscribers_table = Subscriber::$_table;
-    Subscriber::raw_execute(sprintf('
+    Subscriber::rawExecute(sprintf('
       UPDATE %1$s
         JOIN %2$s wu ON %1$s.wp_user_id = wu.id
       SET %1$s.first_name = wu.display_name
@@ -190,7 +190,7 @@ class WP {
     $wp_segment = Segment::getWPSegment();
     $subscribers_table = Subscriber::$_table;
     $wp_mailpoet_subscriber_segment_table = SubscriberSegment::$_table;
-    Subscriber::raw_execute(sprintf('
+    Subscriber::rawExecute(sprintf('
      INSERT IGNORE INTO %s(subscriber_id, segment_id, created_at)
       SELECT mps.id, "%s", CURRENT_TIMESTAMP() FROM %s mps
         WHERE mps.wp_user_id > 0
@@ -199,7 +199,7 @@ class WP {
 
   private static function removeFromTrash() {
     $subscribers_table = Subscriber::$_table;
-    Subscriber::raw_execute(sprintf('
+    Subscriber::rawExecute(sprintf('
       UPDATE %1$s
       SET %1$s.deleted_at = NULL
         WHERE %1$s.wp_user_id IS NOT NULL
diff --git a/lib/Subscribers/ImportExport/Import/Import.php b/lib/Subscribers/ImportExport/Import/Import.php
index c531d894af..27ebbdeec0 100644
--- a/lib/Subscribers/ImportExport/Import/Import.php
+++ b/lib/Subscribers/ImportExport/Import/Import.php
@@ -194,6 +194,7 @@ class Import {
   }
 
   function transformSubscribersData($subscribers, $columns) {
+    $transformed_subscribers = [];
     foreach($columns as $column => $data) {
       $transformed_subscribers[$column] = array_column($subscribers, $data['index']);
     }
@@ -227,6 +228,7 @@ class Import {
     $wp_users = array_filter(array_column($temp_existing_subscribers, 'wp_user_id'));
     // create a new two-dimensional associative array with existing subscribers ($existing_subscribers)
     // and reduce $subscribers_data to only new subscribers by removing existing subscribers
+    $existing_subscribers = [];
     $subscribers_emails = array_flip($subscribers_data['email']);
     foreach($temp_existing_subscribers as $temp_existing_subscriber) {
       $existing_subscriber_key = $subscribers_emails[$temp_existing_subscriber['email']];
diff --git a/lib/Subscribers/ImportExport/Import/MailChimp.php b/lib/Subscribers/ImportExport/Import/MailChimp.php
index d214bbd4d9..b6a96ba9f9 100644
--- a/lib/Subscribers/ImportExport/Import/MailChimp.php
+++ b/lib/Subscribers/ImportExport/Import/MailChimp.php
@@ -7,7 +7,8 @@ class MailChimp {
   public $api_key;
   public $max_post_size;
   public $data_center;
-  public $export_url;
+  private $export_url;
+  private $lists_url;
   const API_KEY_REGEX = '/[a-zA-Z0-9]{32}-[a-zA-Z0-9]{2,4}$/';
 
   function __construct($api_key) {
@@ -44,6 +45,7 @@ class MailChimp {
       return $this->throwException('API');
     }
 
+    $lists = [];
     foreach($response->data as $list) {
       $lists[] = array(
         'id' => $list->id,
@@ -64,6 +66,8 @@ class MailChimp {
     }
 
     $bytes_fetched = 0;
+    $subscribers = [];
+    $header = [];
     foreach($lists as $list) {
       $url = sprintf($this->export_url, $this->data_center, $this->api_key, $list);
       $connection = @fopen($url, 'r');
@@ -71,7 +75,6 @@ class MailChimp {
         return $this->throwException('connection');
       }
       $i = 0;
-      $header = array();
       while(!feof($connection)) {
         $buffer = fgets($connection, 4096);
         if(trim($buffer) !== '') {
@@ -123,6 +126,7 @@ class MailChimp {
   }
 
   function throwException($error) {
+    $errorMessage = __('Unknown MailChimp error.', 'mailpoet');
     switch($error) {
       case 'API':
         $errorMessage = __('Invalid API Key.', 'mailpoet');
@@ -145,4 +149,4 @@ class MailChimp {
     }
     throw new \Exception($errorMessage);
   }
-}
\ No newline at end of file
+}
diff --git a/lib/Tasks/Sending.php b/lib/Tasks/Sending.php
index 4913c8f82a..b9a69cf50c 100644
--- a/lib/Tasks/Sending.php
+++ b/lib/Tasks/Sending.php
@@ -230,7 +230,7 @@ class Sending {
 
   static function getScheduledQueues($amount = self::RESULT_BATCH_SIZE) {
     $wp = new WPFunctions();
-    $tasks = ScheduledTask::table_alias('tasks')
+    $tasks = ScheduledTask::tableAlias('tasks')
       ->select('tasks.*')
       ->join(SendingQueue::$_table, 'tasks.id = queues.task_id', 'queues')
       ->whereNull('tasks.deleted_at')
diff --git a/lib/Util/Sudzy/ValidModel.php b/lib/Util/Sudzy/ValidModel.php
index c8e69d365c..4d7533319a 100644
--- a/lib/Util/Sudzy/ValidModel.php
+++ b/lib/Util/Sudzy/ValidModel.php
@@ -3,6 +3,9 @@ namespace Sudzy;
 
 if(!defined('ABSPATH')) exit;
 
+/**
+ * @method static ORMWrapper|bool create($data=null)
+ */
 abstract class ValidModel extends \Model {
   protected $_validator = null; // Reference to Sudzy validator object
   protected $_validations = array(); // Array of validations
diff --git a/lib/WP/Notice.php b/lib/WP/Notice.php
index a53f699fcf..9a288df38c 100644
--- a/lib/WP/Notice.php
+++ b/lib/WP/Notice.php
@@ -10,6 +10,8 @@ class Notice {
 
   private $type;
   private $message;
+  private $classes;
+  private $data_notice_name;
 
   function __construct($type, $message, $classes = '', $data_notice_name = '') {
     $this->type = $type;
diff --git a/tasks/phpstan/phpstan.neon b/tasks/phpstan/phpstan.neon
index 545e0dd757..4369066f6b 100644
--- a/tasks/phpstan/phpstan.neon
+++ b/tasks/phpstan/phpstan.neon
@@ -2,8 +2,6 @@ parameters:
 	tmpDir: ../../temp/phpstan
 	bootstrap: bootstrap.php
 	ignoreErrors:
-		- '#Access to an undefined property#' # current code suffers from this, it should be fixed & this line removed
-		- '#Static call to instance method MailPoet\\Models\\Model::#'
-		- '#Access to an undefined static property MailPoet\\Models\\Model::#'
 		- '#Function members_register_.+ not found#'
 		- '#MailPoet\\Premium\\DI\\ContainerConfigurator not found#' # this class is not available when premium is not active
+	reportUnmatchedIgnoredErrors: false
diff --git a/tests/integration/Router/Endpoints/ViewInBrowserTest.php b/tests/integration/Router/Endpoints/ViewInBrowserTest.php
index 9528598467..44977169ee 100644
--- a/tests/integration/Router/Endpoints/ViewInBrowserTest.php
+++ b/tests/integration/Router/Endpoints/ViewInBrowserTest.php
@@ -147,12 +147,12 @@ class ViewInBrowserTest extends \MailPoetTest {
     $wp_user = wp_set_current_user(0);
     // when WP user does not have 'manage options' permission, false should be returned
     $wp_user->remove_role('administrator');
-    $view_in_browser->access_control = new AccessControl();
+    $view_in_browser = new ViewInBrowser(new AccessControl());
     expect($this->view_in_browser->_validateBrowserPreviewData($data))->false();
 
     // when WP has 'manage options' permission, data should be returned
     $wp_user->add_role('administrator');
-    $view_in_browser->access_control = new AccessControl();
+    $view_in_browser = new ViewInBrowser(new AccessControl());
     expect($view_in_browser->_validateBrowserPreviewData($data))->equals($data);
   }
 
@@ -168,7 +168,7 @@ class ViewInBrowserTest extends \MailPoetTest {
     );
     $data->preview = true;
     wp_set_current_user(1);
-    $view_in_browser->access_control = new AccessControl();
+    $view_in_browser = new ViewInBrowser(new AccessControl());
     $result = $view_in_browser->_validateBrowserPreviewData($data);
     expect($result->subscriber->id)->equals(1);
   }