Ring, John C wrote:
My boss is twisting off today because he got 350 messages marked [SPAM] over the weekend. His Reaction is to "Bounce em all, Let the isps sort it out."
[snip]
We use amavisd-new to run SA from Postfix. Below W it is classified as Ham, above X andWhat you want to do, IMO, is run SpamAssassin during the SMTP session, such as with http://duncanthrax.net/exiscan-acl/. Then reject messages with a very high score, but simply label and deliver messages for a lower spam score. For example, reject mail scoring 15 or higher, mark and deliver if 5 or over, and classify as ham if the score is below 5.
Other MTAs provide other ways of doing this as well.
below Y it is classified as Spam, but still passed through, above Y and below Z it is rejected,
but a bounce message is sent, just in case, and above Z it is rejected with no bounce message.
The bounce for scores above Y and below Z allows a few false positives to get whitelisted
later and resent without having to quarantine and examine, but doesn't result in a lot of backscatter.
-Bill
