Mark Martinec wrote:
If scanning at the MTA level with amavisd-new, a synthetic Return-Path is prepended to a copy of a message that is given to SA for examination. Much like David B Funk says a sendmail-SA-milter does.
MIMEDefang does this as well. It synthesizes Received and Return-Path when passing the message to SpamAssassin.
There was some discussion a month or so back on providing a way for filters to add custom headers to the SA call, so you could do things like X-Envelope-To. Two people posted the methods they used, but the author wasn't quite satisfied with either method. Last I remember reading, he said he was looking into another way to do it.
-- Kelson Vibber SpeedGate Communications <www.speed.net>
