diff --git a/mailpoet/lib/Automation/Engine/Control/SubjectTransformerHandler.php b/mailpoet/lib/Automation/Engine/Control/SubjectTransformerHandler.php
index c9474f6075..984c370a35 100644
--- a/mailpoet/lib/Automation/Engine/Control/SubjectTransformerHandler.php
+++ b/mailpoet/lib/Automation/Engine/Control/SubjectTransformerHandler.php
@@ -5,7 +5,7 @@ namespace MailPoet\Automation\Engine\Control;
 use MailPoet\Automation\Engine\Data\Automation;
 use MailPoet\Automation\Engine\Data\AutomationRun;
 use MailPoet\Automation\Engine\Data\Step as StepData;
-use MailPoet\Automation\Engine\Data\Subject as SubjectData;
+use MailPoet\Automation\Engine\Data\Subject;
 use MailPoet\Automation\Engine\Integration\Step;
 use MailPoet\Automation\Engine\Integration\SubjectTransformer;
 use MailPoet\Automation\Engine\Integration\Trigger;
@@ -97,7 +97,42 @@ class SubjectTransformerHandler {
   }
 
   /**
-   * @return SubjectData[]|null
+   * @param Trigger $trigger
+   * @param Subject ...$subjects
+   * @return Subject[]
+   */
+  public function provideAllSubjects(Trigger $trigger, Subject ...$subjects): array {
+    $allSubjectsKeys = $this->subjectKeysForTrigger($trigger);
+    $allSubjectKeyTargets = array_diff($allSubjectsKeys, array_map(
+      function(Subject $subject): string {
+        return $subject->getKey();
+      },
+      $subjects
+    ));
+
+    $allSubjects = [];
+    foreach ($subjects as $existingSubject) {
+      $allSubjects[$existingSubject->getKey()] = $existingSubject;
+    }
+    foreach ($allSubjectKeyTargets as $target) {
+      if (isset($allSubjects[$target])) {
+        continue;
+      }
+      foreach ($subjects as $subject) {
+        $transformedSubject = $this->transformSubjectTo($subject, $target);
+        if ($transformedSubject) {
+          $allSubjects[$transformedSubject->getKey()] = $transformedSubject;
+        }
+      }
+    }
+    while (count($allSubjects) < count($allSubjectsKeys)) {
+      $allSubjects = $this->provideAllSubjects($trigger, ...array_values($allSubjects));
+    }
+    return array_values($allSubjects);
+  }
+
+  /**
+   * @return Subject[]|null
    */
   public function transformSubjectData(string $target, AutomationRun $automationRun): ?array {
     $automation = $this->automationStorage->getAutomation($automationRun->getAutomationId(), $automationRun->getVersionId());
@@ -108,18 +143,26 @@ class SubjectTransformerHandler {
     $transformedSubjects = [];
     $subjects = $automationRun->getSubjects();
     foreach ($subjects as $subject) {
-      $transformerChain = $this->getTransformerChain($subject->getKey(), $target);
-      if (!$transformerChain) {
+      $transformedSubject = $this->transformSubjectTo($subject, $target);
+      if (!$transformedSubject) {
         continue;
       }
-      foreach ($transformerChain as $transformer) {
-        $subject = $transformer->transform($subject);
-      }
       $transformedSubjects[] = $subject;
     }
     return count($transformedSubjects) > 0 ? $transformedSubjects : null;
   }
 
+  private function transformSubjectTo(Subject $subject, string $target): ?Subject {
+    $transformerChain = $this->getTransformerChain($subject->getKey(), $target);
+    if (!$transformerChain) {
+      return null;
+    }
+    foreach ($transformerChain as $transformer) {
+      $subject = $transformer->transform($subject);
+    }
+    return $subject;
+  }
+
   /**
    * @return SubjectTransformer[]
    */
diff --git a/mailpoet/lib/Automation/Engine/Control/TriggerHandler.php b/mailpoet/lib/Automation/Engine/Control/TriggerHandler.php
index b1921adcf8..11b14b0e4a 100644
--- a/mailpoet/lib/Automation/Engine/Control/TriggerHandler.php
+++ b/mailpoet/lib/Automation/Engine/Control/TriggerHandler.php
@@ -29,15 +29,20 @@ class TriggerHandler {
   /** @var AutomationRunStorage */
   private $automationRunStorage;
 
+  /** @var Functions  */
   private $wp;
 
+  /** @var SubjectTransformerHandler */
+  private $subjectTransformerHandler;
+
   public function __construct(
     ActionScheduler $actionScheduler,
     SubjectLoader $subjectLoader,
     WordPress $wordPress,
     AutomationStorage $automationStorage,
     AutomationRunStorage $automationRunStorage,
-    Functions $wp
+    Functions $wp,
+    SubjectTransformerHandler $subjectTransformerHandler
   ) {
     $this->actionScheduler = $actionScheduler;
     $this->wordPress = $wordPress;
@@ -45,6 +50,7 @@ class TriggerHandler {
     $this->automationRunStorage = $automationRunStorage;
     $this->subjectLoader = $subjectLoader;
     $this->wp = $wp;
+    $this->subjectTransformerHandler = $subjectTransformerHandler;
   }
 
   public function initialize(): void {
@@ -53,6 +59,7 @@ class TriggerHandler {
 
   /** @param Subject[] $subjects */
   public function processTrigger(Trigger $trigger, array $subjects): void {
+    $subjects = $this->subjectTransformerHandler->provideAllSubjects($trigger, ...$subjects);
     $automations = $this->automationStorage->getActiveAutomationsByTrigger($trigger);
     foreach ($automations as $automation) {
       $step = $automation->getTrigger($trigger->getKey());