- set content-length when saving message source

program/steps/mail/viewsource.inc

@@ -37,7 +37,8 @@ if ($uid = get_input_value('_uid', RCUBE_INPUT_GET))
       $filename = rawurlencode($filename);
     else
       $filename = addcslashes($filename, '"');
-      
+
+    header("Content-Length: {$headers->size}");
     header("Content-Disposition: attachment; filename=\"$filename\"");
   }