On Thu, 17 May 2007, ahv [ at ] avantel [ dot ] ca wrote: > Milter-Greylist with a 20 minute delay > - that eliminates a huge number of spam > - saves tons of cycles for the next step > Mailscanner with Clamav and Spamassassin > - spamassassin is almost useless for "image" spam > - marking an email as spam and forwarding is pointless > if it's going to another mailserver > Sendmail is configured to NOT forward mail except for domains I host. > Several DNS Blacklists (sendmail) > - getting less reliable I am using a similar setup with postfix and finding it quite effective. I personally used to get 200-300 spams per day (filtered) and now that's down to < 10. I use greylisting timeout of 6 minutes. That can still cause undeliverable mail but appears to cause few, in fact only one that I am aware of lately and that I whitelisted. I see avantel have two mail exchanger addresses. Do these terminate on the same host (i.e. with the same rules), or is there a secondary mail system? If you are relaying mail from your second MX and it does not implement the same rigourous rules as your primary MX then a lot of spam will get injected that way (to your secondary). > - marking an email as spam and forwarding is pointless I disagree, depending on what you mean as "marking". I prefer to tag all incoming email (I'm handling a number of NGO domains) with SA and let each user determine and adjust their filter policy and be accountable to themselves for missing emails. > My system rejects thousands of emails per day through the > "grey-list", accepts several 100's of emails of which perhaps 30% > spam. This seems like a reasonable rejection ratio, in my limited experience. Brett