Milter-greylist

Hi,

is it possible to blacklist a server only if it's blacklisted an all given
blacklists? Before running emails into spamassassin I like to blacklist a
server if its IP is found on at least two blacklists. I found this howto on
http://milter-greylist.wikidot.com/white-black-grey but it looks like that
an server is blacklisted as soon as its IP matches one of the given
blacklists?

Ciao
Marcus