Hi, On Fri, 5 Mar 2004 10:23:42 -0000 (GMT) "Andy Blanchard" <[EMAIL PROTECTED]> wrote:
> While the technique described in this article is intended for > implementation at the MTA level, it still makes for interesting reading > that's worth a look. There seem to be a few ideas in here that might be > useful in enhancing the reliability of SpamAssassin's Auto-Whitelisting > feature as well, especially the concept of the "triplet". > > Anyway, here's the link for your perusal: > > http://projects.puremagic.com/greylisting/ The hard part is reliably getting the mail envelope information & IP address (or /24) into SA, though I expect those elements would make very good Bayes tokens. What might work even better is scanning your sent mail folder for recipients and adding those to AWL on the assumption that you don't correspond directly with spammers. Greylisting kills proxy spam dead with only a minor delay to some mail with a little manual whitelisting of broken MTAs (ancient Groupwise) and large email farms that retry from different IP addresses. Counterintuitively, greylisting also saves bandwidth because the SMTP connection and tempfail traffic is substantially smaller than spam message bodies (you tempfail before reaching the SMTP DATA phase.) Still, if you can't accept a one time 5-60min delay in mail from new people, the technique is probably not for you. -- Bob
