diff --git a/mailpoet/lib/Models/ModelValidator.php b/mailpoet/lib/Models/ModelValidator.php
index c53410b644..17534d858c 100644
--- a/mailpoet/lib/Models/ModelValidator.php
+++ b/mailpoet/lib/Models/ModelValidator.php
@@ -6,10 +6,17 @@ use MailPoet\DI\ContainerWrapper;
 use MailPoet\Services\Validator;
 use MailPoet\Util\Helpers;
 
+/**
+ * @deprecated This class is deprecated. Use \MailPoet\Services\Validator instead. This class can be removed after 2024-05-30.
+ */
 class ModelValidator extends \MailPoetVendor\Sudzy\Engine {
   public $validators;
 
+  /**
+   * @deprecated
+   */
   public function __construct() {
+    self::deprecationError(__METHOD__);
     parent::__construct();
     $this->validators = [
       'validEmail' => 'validateEmail',
@@ -18,7 +25,11 @@ class ModelValidator extends \MailPoetVendor\Sudzy\Engine {
     $this->setupValidators();
   }
 
+  /**
+   * @deprecated
+   */
   private function setupValidators() {
+    self::deprecationError(__METHOD__);
     $_this = $this;
     foreach ($this->validators as $validator => $action) {
       $this->addValidator($validator, function($params) use ($action, $_this) {
@@ -30,12 +41,20 @@ class ModelValidator extends \MailPoetVendor\Sudzy\Engine {
     }
   }
 
+  /**
+   * @deprecated
+   */
   public function validateEmail($email) {
+    self::deprecationError(__METHOD__);
     $validator = ContainerWrapper::getInstance()->get(Validator::class);
     return $validator->validateEmail($email);
   }
 
+  /**
+   * @deprecated
+   */
   public function validateRenderedNewsletterBody($newsletterBody) {
+    self::deprecationError(__METHOD__);
     if (is_serialized($newsletterBody)) {
       $newsletterBody = unserialize($newsletterBody);
     } else if (Helpers::isJson($newsletterBody)) {
@@ -43,4 +62,11 @@ class ModelValidator extends \MailPoetVendor\Sudzy\Engine {
     }
     return (is_null($newsletterBody) || (is_array($newsletterBody) && !empty($newsletterBody['html']) && !empty($newsletterBody['text'])));
   }
+
+  private static function deprecationError($methodName) {
+    trigger_error(
+      'Calling ' . esc_html($methodName) . ' is deprecated and will be removed. Use \MailPoet\Services\Validator instead.',
+      E_USER_DEPRECATED
+    );
+  }
 }