auto blacklist email and IP but after forwarding email to some special mailbox

Hello

I have some idea, maybe somebody has idea how to.

I have postfix and cyrus on opensuse with all goodies like spamassasin etc, but still getting some emails i don't want.

I have idea how to easy prevent it, but i don't know howto :)

Idea is when i get unwanted email, i forward it to for eg email blockit@mydomain, some script reads this mailbox and automatically add email and IP to postfix blacklist database.

Is this doable?

Thanks.