[fetchmail] Help: Posfix and Fetchmail

Thanks Rob for an advice.

FYI, I have been trying all possible combination of smtphost, smtpaddress,
and smtpname. And yet Fetchmail still can't forward messages to my Postfix.
As a result, it forward it to the postmaster on localhost i.e. "sthay".

Please advice me more or point me out to the place where I can do some basic
research myself.

Thanks lots in advance.

Sot