[Mimedefang] Questions about stream_by_recipient and problems it creates.

[Jan-Pieter Cornet]

On Tue, Jan 23, 2007 at 03:28:49PM -0500, David F. Skoll wrote:
> > 1.  Detect the spam and reject it in filter_end which is very clean, but
> > causes problems when there are two recipients, one which wants the
> > message, and one who wants it to be bounced as spam.
> 
> > 2.  Call stream_by_recipient and re-queue the message for each recipient
> > causing all messages to multiple recipients to be accepted then later
> > rejected if detected as spam.  This also causes a new bounce message
> > sourced from MAILER-DAEMON to be sent to the sender, which in the case
> > of spam, is almost always spoofed.
> 
> Our commercial CanIt-PRO product uses a third solution:
> 
> 3) If all recipients have the same settings and rules, reject the spam
> in filter_end.  Otherwise, remail copies.  If an e-mail originating
> from 127.0.0.1 is rejected as spam, we call action_discard instead of
> action_bounce.  Three years ago, I would have said this was a bad solution
> because it silently discarded e-mail.  Today, unfortunately, I am of the
> opinion that it's the only viable way.

A fourth option is to introduce a "spam folder", where you file
suspected spams. We already use this currently. Then if you cannot
reject an email for one user (because another user does want to
receive the email), flag the message to be delivered to the 
spam folder.

Or combine this with option 3 by david, and introduce another
threshhold score above which you can junk messages instead of
delivering or rejecting them.

Oh, and a fifth option is to detect this possibility at filter_recipient
time, and tempfail recipients that have a filter profile that isn't
on par with the filter of the first recipient. Optionally only for
hosts that have some sort of flag set.

-- 
Jan-Pieter Cornet <johnpc at xs4all.nl>
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