Inbox and Outbox After you connect with the FTP Server, your FTP Client will show the file structure that is available on your local machine when navigating through the Inbox or Outbox using the FTP CWD command. The Host machine, FTP Server, will also have a specific folders designated as Inbox and Outbox. These folders are used to either upload your files to the FTP Server using the PUT command, or to download files from the FTP Server using the GET command. Inbox is used to download files and Outbox is used to upload files.