diff --git a/plugins/enigma/lib/enigma_mime_message.php b/plugins/enigma/lib/enigma_mime_message.php
index e21c63ba8..6c9437809 100644
--- a/plugins/enigma/lib/enigma_mime_message.php
+++ b/plugins/enigma/lib/enigma_mime_message.php
@@ -242,8 +242,6 @@ class enigma_mime_message extends Mail_mime
             }
 
             $this->headers = array_merge($this->headers, $headers);
-
-            return;
         }
         else {
             $output = $message->encode($boundary, $skip_head);
@@ -253,9 +251,16 @@ class enigma_mime_message extends Mail_mime
             }
 
             $this->headers = array_merge($this->headers, $output['headers']);
+        }
 
-            return $output['body'];
+        // remember the boundary used, in case we'd handle headers() call later
+        if (empty($boundary) && !empty($this->headers['Content-Type'])) {
+            if (preg_match('/boundary="([^"]+)/', $this->headers['Content-Type'], $m)) {
+                $this->build_params['boundary'] = $m[1];
+            }
         }
+
+        return $filename ? null : $output['body'];
     }
 
     /**