Select 8 KB of message part for headers (to make sure we get them all)

program/lib/Roundcube/rcube_message.php

@@ -322,7 +322,7 @@ class rcube_message
 
             // parse headers from message/rfc822 part
             if (!isset($structure->headers['subject'])) {
-                list($headers, $dump) = explode("\r\n\r\n", $this->get_part_content($structure->mime_id, null, true, 4096));
+                list($headers, $dump) = explode("\r\n\r\n", $this->get_part_content($structure->mime_id, null, true, 8192));
                 $structure->headers = rcube_mime::parse_headers($headers);
             }
         }