diff --git a/src/Transport/ScalewayApiTransport.php b/src/Transport/ScalewayApiTransport.php
index 067eaa0..95a7b98 100644
--- a/src/Transport/ScalewayApiTransport.php
+++ b/src/Transport/ScalewayApiTransport.php
@@ -61,7 +61,7 @@ protected function doSendApi(SentMessage $sentMessage, Email $email, Envelope $e
             throw new HttpTransportException('Unable to send an email: '.$result['message'].' Details: '.print_r($result, true), $response);
         }
 
-        $sentMessage->setMessageId($result['id']); // TODO: what is message_id
+        $sentMessage->setMessageId($result['emails'][0]['id']); // TODO: what is message_id
 
         return $response;
     }