At 12:40 PM -0400 4/30/07, Steve Friedman wrote: >On Mon, 30 Apr 2007, Guy Fraser wrote: > >> On Fri, 2007-04-27 at 22:04 -0400, Tony Nelson wrote: >>>> >>>> I will look into greylisting and see what I can come up with. > >Greylisting is one of the biggest winners here. We've cut the spam load >so much that spam assassin now catches almost nothing. > >>> >>> Also look at Early Talker, called Greet Pause in sendmail. It's when the >>> sender has sent the whole message at once, rather than having a proper SMTP >>> conversation. Such messages can be presumed spam, and discarded with no >>> further action. >> >> Hmm... That looks like a reasonable idea. >> > >The general consensus on the postfix mailing idea is that Greet Pause is a >bad idea (TM). What it ends up doing is (a) delay legitimate mail and (b) >DoS your own server as you now take longer to handle legitimate mail. Any >mail source that would fail greet pause will also fail numerous other >checks that don't inconvenience your intended users (and your own system). Well, don't forget that greylisting will delay each new legitimate mail sender by a while (maybe a few hours), requires maintaining whitelists for the server farms of large email providers (AOL, etc.) or email from them may take much more than 4 hours to get through, and the mail must be handled twice by your server rather than just once. -- ____________________________________________________________________ TonyN.:' <mailto:tonynelson@xxxxxxxxxxxxxxxxx> ' <http://www.georgeanelson.com/>
