There are several different mechanisms used by FTP proxy servers to authenticate and forward FTP requests and responses. (more information about FTP proxy mechanisms) Unfortunately, you must know what kind of FTP proxy server you have in order to get your FTP client to work correctly (including Chilkat FTP2).
One such mechanism is "USER username@site". The FTP client connects to the FTP proxy and authenticates by passing both the username and destination FTP site in the USER command. The FTP Proxy establishes the connection with the target FTP server and authenticates using the username. Once authenticated, all FTP commands are automatically forwarded from the FTP proxy to the FTP server, and responses are forwarded back to the client.
These are the Chilkat FTP2 property settings required for this type of FTP proxy.
ftp.ProxyMethod = 2
ftp.ProxyHostname = "ftp.someProxyServer.com"
ftp.Hostname = "ftp.destFtpServer.com"
ftp.Username = "myFtpUsername"
ftp.Password = "myFtpPassword"