diff --git a/app/Services/SandboxService.php b/app/Services/SandboxService.php
index f136e53..719c1ab 100644
--- a/app/Services/SandboxService.php
+++ b/app/Services/SandboxService.php
@@ -69,18 +69,21 @@ class SandboxService
             $content .= "\n";
         }
 
+        $tmp = tempnam(sys_get_temp_dir(), 'mw_sandbox_');
         try {
-            file_put_contents($file, $content);
+            file_put_contents($tmp, $content);
         } catch (\Throwable $e) {
+            @unlink($tmp);
             return ['ok' => false, 'message' => 'Fehler beim Schreiben: ' . $e->getMessage()];
         }
 
         $out  = [];
         $code = 0;
-        exec('postmap ' . escapeshellarg($file) . ' 2>&1', $out, $code);
+        exec('sudo -n /usr/local/sbin/mailwolt-sandbox-sync ' . escapeshellarg($tmp) . ' 2>&1', $out, $code);
+        @unlink($tmp);
 
         if ($code !== 0) {
-            return ['ok' => false, 'message' => 'postmap Fehler: ' . implode(' ', $out)];
+            return ['ok' => false, 'message' => 'Sync-Fehler: ' . implode(' ', $out)];
         }
 
         return ['ok' => true, 'message' => 'Transport-Datei synchronisiert (' . count($lines) . ' Einträge).'];