These are more appropriately procmail questions, but

Do you know if this ruleset will process before or after attempted delivery
to the user (and thus triggering the .forward file)? Is there a difference
between using /usr/bin/spamassassin versus using /usr/bin/spamc ? And can I
still use this rule to dump spam with high scores?:
:0
* ^X-Spam-Level: \*\*\*\*\*\*\*\*\*\*
/dev/null

> :0fwhb
> | /usr/bin/spamassassin
> :0H
> * ^X-Spam-Status: Yes
> /var/spool/mail/spam