How-to set up and configure policyd-weight for additional spam prevention

Simple how-to for installing and configuring policyd-weight policy daemon. Policyd-weight sits inline with Postfix and can reject mails before the data transaction. This is great for quickly IDing spammers and rejecting them before soaking up bandwidth and processing via spamassassin. How-to is geared towards Gentoo Linux, but can be easily applied to others.