[fetchmail]mail forward between ISPs

[Picio]

Hello,
I need to configure a script or an application that takes my mail from
one remote ISP account and send everything to another remote account.
This is because my ISP block me when I try to download my mail from
other providers.
I know that fetchmail can help but I don't know how to configure It.
Maybe I have to do a Pipe between fetchmail and smtpclient timely
based with a cron job?

many thanks.
Picio