diff --git a/mailpoet/lib/Newsletter/Sending/ScheduledTaskSubscribersRepository.php b/mailpoet/lib/Newsletter/Sending/ScheduledTaskSubscribersRepository.php
index 2678638ea9..3dc1215b7c 100644
--- a/mailpoet/lib/Newsletter/Sending/ScheduledTaskSubscribersRepository.php
+++ b/mailpoet/lib/Newsletter/Sending/ScheduledTaskSubscribersRepository.php
@@ -7,6 +7,7 @@ use MailPoet\Entities\ScheduledTaskEntity;
 use MailPoet\Entities\ScheduledTaskSubscriberEntity;
 use MailPoet\Entities\SubscriberEntity;
 use MailPoet\InvalidStateException;
+use MailPoetVendor\Doctrine\ORM\QueryBuilder;
 
 /**
  * @extends Repository<ScheduledTaskSubscriberEntity>
@@ -53,4 +54,45 @@ class ScheduledTaskSubscribersRepository extends Repository {
     $this->flush();
     return $taskSubscriber;
   }
+
+  public function countSubscriberIdsBatchForTask(int $taskId, int $lastProcessedSubscriberId): int {
+    $queryBuilder = $this->entityManager
+      ->createQueryBuilder()
+      ->select('count(sts.subscriber)');
+    $queryBuilder = $this->prepareSubscriberIdsBatchForTaskQuery($queryBuilder, $taskId, $lastProcessedSubscriberId);
+    $countSubscribers = $queryBuilder
+      ->getQuery()
+      ->getSingleScalarResult();
+
+    if (is_numeric($countSubscribers)) {
+      return (int)$countSubscribers;
+    } else {
+      return 0;
+    }
+  }
+
+  public function getSubscriberIdsBatchForTask(int $taskId, int $lastProcessedSubscriberId, int $limit): array {
+    $queryBuilder = $this->entityManager
+      ->createQueryBuilder()
+      ->select('IDENTITY(sts.subscriber) AS subscriber_id');
+    $queryBuilder = $this->prepareSubscriberIdsBatchForTaskQuery($queryBuilder, $taskId, $lastProcessedSubscriberId);
+    $subscribersIds = $queryBuilder
+      ->orderBy('sts.subscriber', 'asc')
+      ->setMaxResults($limit)
+      ->getQuery()
+      ->getSingleColumnResult();
+
+    return $subscribersIds;
+  }
+
+  private function prepareSubscriberIdsBatchForTaskQuery(QueryBuilder $queryBuilder, int $taskId, int $lastProcessedSubscriberId): QueryBuilder {
+    return $queryBuilder
+      ->from(ScheduledTaskSubscriberEntity::class, 'sts')
+      ->andWhere('sts.task = :taskId')
+      ->andWhere('sts.subscriber > :lastProcessedSubscriberId')
+      ->andWhere('sts.processed = :status')
+      ->setParameter('taskId', $taskId)
+      ->setParameter('lastProcessedSubscriberId', $lastProcessedSubscriberId)
+      ->setParameter('status', ScheduledTaskSubscriberEntity::STATUS_UNPROCESSED);
+  }
 }
diff --git a/mailpoet/lib/Tasks/Subscribers/BatchIterator.php b/mailpoet/lib/Tasks/Subscribers/BatchIterator.php
index 1d52b5a928..a7668dfd6a 100644
--- a/mailpoet/lib/Tasks/Subscribers/BatchIterator.php
+++ b/mailpoet/lib/Tasks/Subscribers/BatchIterator.php
@@ -2,7 +2,8 @@
 
 namespace MailPoet\Tasks\Subscribers;
 
-use MailPoet\Models\ScheduledTaskSubscriber;
+use MailPoet\DI\ContainerWrapper;
+use MailPoet\Newsletter\Sending\ScheduledTaskSubscribersRepository;
 
 /**
  * @implements \Iterator<null, array>
@@ -13,6 +14,9 @@ class BatchIterator implements \Iterator, \Countable {
   private $lastProcessedId = 0;
   private $batchLastId;
 
+  /** @var ScheduledTaskSubscribersRepository */
+  private $scheduledTaskSubscribersRepository;
+
   public function __construct(
     $taskId,
     $batchSize
@@ -24,6 +28,7 @@ class BatchIterator implements \Iterator, \Countable {
     }
     $this->taskId = (int)$taskId;
     $this->batchSize = (int)$batchSize;
+    $this->scheduledTaskSubscribersRepository = ContainerWrapper::getInstance()->get(ScheduledTaskSubscribersRepository::class);
   }
 
   public function rewind(): void {
@@ -35,11 +40,7 @@ class BatchIterator implements \Iterator, \Countable {
    */
   #[\ReturnTypeWillChange]
   public function current() {
-    $subscribers = $this->getSubscribers()
-      ->orderByAsc('subscriber_id')
-      ->limit($this->batchSize)
-      ->findArray();
-    $subscribers = array_column($subscribers, 'subscriber_id');
+    $subscribers = $this->scheduledTaskSubscribersRepository->getSubscriberIdsBatchForTask($this->taskId, $this->lastProcessedId, $this->batchSize);
     $this->batchLastId = end($subscribers);
     return $subscribers;
   }
@@ -61,13 +62,6 @@ class BatchIterator implements \Iterator, \Countable {
   }
 
   public function count(): int {
-    return $this->getSubscribers()->count();
-  }
-
-  private function getSubscribers() {
-    return ScheduledTaskSubscriber::select('subscriber_id')
-      ->where('task_id', $this->taskId)
-      ->whereGt('subscriber_id', $this->lastProcessedId)
-      ->where('processed', ScheduledTaskSubscriber::STATUS_UNPROCESSED);
+    return $this->scheduledTaskSubscribersRepository->countSubscriberIdsBatchForTask($this->taskId, $this->lastProcessedId);
   }
 }