You'll wonder no more how to manipulate SSIS Package Variables via Script Tasks, once you're done reading this little tidbit.

Es bleibt nur die Möglichkeit, in der SSIS Script Task den Zugriffscode auf die CDO-Komponente in einem eigenen Thread zu starten, der explizit als STA-Thread gestartet wurde: ...

If you need to be a little more advanced with your FTP you can write a Script Task that utilizes FTP objects. As luck would have it, setting up FTP in an SSIS script will be the topic of ...