We're working on integrating amavisd-new/spamassassin/f-prot into IMGate. I'm comparing the differences between the two methods of doing this: content_filter and smtpd_proxy_filter
With content_filter, Postfix accepts the email and then sends it through the filter, so rejecting during the smtp session is not possible. However with smtpd_proxy_filter, Postfix sends the email through the filter after the DATA command but prior to issuing the smtp response, so rejecting during the smtp session is possible. Has anybody tried using smtpd_proxy_filter? I'd like to use that method, but I'm concerned that it will tie up too many active smtpd processes causing a bottleneck. If anybody has any comments to share on this, I am very interested. Thanks, Bill
