> perhaps just having it accept from addresses that are subscribed to AT
> LEAST one of the lists (not necessarily the one that is being written
> to) - this would prevent outside spam, while allowing crossposting. of
> course, spammers could get smart and subscribe to a list..

Unfortunately, this doesn't work.
Think about the following cross-postings:
e.g.
	XFree86 people try to cross-post XFree86 list + NetBSD list.
	FreeBSD people try to cross-post FreeBSD list + NetBSD list.
	Linux people try to cross-post Linux list + NetBSD list.

This is why we use content based filter against SPAMs.
--
port-dreamcast-owner@netbsd.org