diff --git a/src/Model/AbstractModel.php b/src/Model/AbstractModel.php
index 41a1838..9c7ce4f 100644
--- a/src/Model/AbstractModel.php
+++ b/src/Model/AbstractModel.php
@@ -120,7 +120,7 @@ public function setApiCredentials(ApiCredentials $credentials = null)
      */
     public function __set($key, $value)
     {
-        if (!$value) {
+        if ($value) {
             $this->data[$key] = $value;
         }
 
@@ -191,7 +191,7 @@ abstract public function save();
      *
      * @return array
      */
-    public static function getConfigurableFields()
+    public function getConfigurableFields()
     {
         return static::$configurableFields;
     }
diff --git a/src/Model/NewsletterAttribute.php b/src/Model/NewsletterAttribute.php
index be299a2..8b2a033 100644
--- a/src/Model/NewsletterAttribute.php
+++ b/src/Model/NewsletterAttribute.php
@@ -24,7 +24,8 @@
  * @method NewsletterAttribute setId($id)
  * @method NewsletterAttribute setName($name)
  * @method NewsletterAttribute setType($type) One of ['number', 'date', 'boolean', 'text']
- * @method NewsletterAttribute setSubType($subType)
+ * @method NewsletterAttribute setSubType($subType) One of the ['text', 'email', 'color', 'url', 'tel', 'date',
+ *         'datetime', 'time', 'integer', 'float']
  * @method string getId()
  * @method string getCompanyId()
  * @method string getName()
diff --git a/src/Model/NewsletterRecipient.php b/src/Model/NewsletterRecipient.php
index da40e68..4bac5a3 100644
--- a/src/Model/NewsletterRecipient.php
+++ b/src/Model/NewsletterRecipient.php
@@ -63,6 +63,16 @@ class NewsletterRecipient extends AbstractModel implements ModelDeletableInterfa
         'is_blacklisted',
     ];
 
+    /**
+     * Get all configurable fields
+     *
+     * @return array
+     */
+    public function getConfigurableFields()
+    {
+        return array_keys($this->getData());
+    }
+
     /** @noinspection MoreThanThreeArgumentsInspection
      *
      * Find recipients by a selected list and group
@@ -77,6 +87,7 @@ class NewsletterRecipient extends AbstractModel implements ModelDeletableInterfa
      * @throws \InvalidArgumentException
      * @throws \RuntimeException
      * @throws \LogicException
+     * @throws \League\OAuth2\Client\Provider\Exception\IdentityProviderException
      */
     public static function findByListAndGroup(
         $lid,
@@ -109,6 +120,7 @@ public static function findByListAndGroup(
      * @throws \InvalidArgumentException
      * @throws \RuntimeException
      * @throws \LogicException
+     * @throws \League\OAuth2\Client\Provider\Exception\IdentityProviderException
      */
     public static function findByList($lid, GetParameters $getParams = null, ApiCredentials $credentials = null)
     {
@@ -132,8 +144,10 @@ public static function findByList($lid, GetParameters $getParams = null, ApiCred
      *
      * @return void
      *
+     * @throws \InvalidArgumentException
      * @throws \RuntimeException
      * @throws \LogicException
+     * @throws \League\OAuth2\Client\Provider\Exception\IdentityProviderException
      */
     public function addToGroup($gid)
     {
@@ -158,8 +172,10 @@ public function addToGroup($gid)
      *
      * @return void
      *
+     * @throws \InvalidArgumentException
      * @throws \RuntimeException
      * @throws \LogicException
+     * @throws \League\OAuth2\Client\Provider\Exception\IdentityProviderException
      */
     public function removeFromGroup($gid)
     {
@@ -182,8 +198,10 @@ public function removeFromGroup($gid)
      *
      * @return self
      *
+     * @throws \InvalidArgumentException
      * @throws \RuntimeException
      * @throws \LogicException
+     * @throws \League\OAuth2\Client\Provider\Exception\IdentityProviderException
      */
     public function save()
     {
@@ -210,8 +228,10 @@ public function save()
      *
      * @return void
      *
+     * @throws \InvalidArgumentException
      * @throws \RuntimeException
      * @throws \LogicException
+     * @throws \League\OAuth2\Client\Provider\Exception\IdentityProviderException
      */
     public function delete()
     {
@@ -249,8 +269,10 @@ public function delete()
      *
      * @return self
      *
+     * @throws \InvalidArgumentException
      * @throws \RuntimeException
      * @throws \LogicException
+     * @throws \League\OAuth2\Client\Provider\Exception\IdentityProviderException
      */
     private function update()
     {