FtpClient client = new FtpClient("ftp", "user", "pwd");
        client.DataConnectionType = FtpDataConnectionType.PASV;
        client.EncryptionMode = FtpEncryptionMode.Explicit;
        client.SslProtocols = System.Security.Authentication.SslProtocols.Tls11;
        client.ValidateCertificate += new FtpSslValidation(OnValidateCertificate);
        client.Encoding = System.Text.Encoding.ASCII;
        client.UploadFile(@"C:\Test\Test.txt", "/archive/Test.txt", FtpExists.Overwrite, true, FtpVerify.Retry);
         client.Disconnect();