• Automatic authentication will be done with Identd protocol if you have a Identd server running on your host.

• Callback authentication using FTP server. If you know the password to login user@host then you are supposed to be user@host. Let the DeleGate inspect it sending an authorization information as follows:
  
  Username: user@host
  Password: password for the user@host
  
  If DeleGate succeed to login the host with given user name and password, then you are proved to be user@host.