title: Don't always get a 226 Transfer OK at the end of an FTP upload
body: <p>With an FTP client I've written I will sometimes receive a <code>226 Transfer OK</code> message from the FileZilla server after an upload completes, and sometimes I won't ever receive anything. And it's not that the client disconnected before the <code>226 Transfer OK</code> was received, because I can see on the server that FileZilla never sent it.</p>
  
  <p>I need to know when the server has received the complete upload, because I otherwise do not know if the whole file made it to the network before I close the connection.</p>
  
  <p>Any ideas what might cause the unreliability of the <code>226 Transfer OK</code> message? What actually triggers it to be sent?</p>