Avoid auto-responders when possible

src/Packagist/WebBundle/Model/PackageManager.php

@@ -150,6 +150,8 @@ class PackageManager
                     ->setBody($body)
                 ;
 
+                $message->getHeaders()->addTextHeader('X-Auto-Response-Suppress', 'OOF, DR, RN, NRN, AutoReply');
+
                 try {
                     $this->instantMailer->send($message);
                 } catch (\Swift_TransportException $e) {
@@ -184,6 +186,8 @@ class PackageManager
             ->setBody($body)
         ;
 
+        $message->getHeaders()->addTextHeader('X-Auto-Response-Suppress', 'OOF, DR, RN, NRN, AutoReply');
+
         try {
             $this->mailer->send($message);
         } catch (\Swift_TransportException $e) {