steve mcconville xzlpuvywtfbisdzgmailcom 08112007 proinnsias breathnach wrote thu nov 08 2007 100842am 0000 michele neylon blacknight wrote kieran osullivan wrote looking advice antispam strategy two different approaches effectively blocking spam content based origin based usually combination two optimal origin based greylisting realtime blacklists spamhaus etc commtouch content based many content based approaches work amavisdnew dspam spamassassin checksum razor pyzor dcc fuzzyocr spf dubious effectiveness would recommend challengeresponse steev httpwwwdaikaijuorguksteve thu 07 aug 2008 192004 0000 ilug advice antispam strategyblocking software