Re: [Exim] Multiple recipients and whitelist checks

On Sat, 2004-07-17 at 10:49 +0100, Alan J. Flavell wrote:
> On Sat, 17 Jul 2004, David Woodhouse wrote:
>
> > I've been toying with this kind of idea too. But why split the message
> > unless the data payload actually causes a different _result_ for
> > different recipients?
>
> Because at the time you're accepting the individual recipients, you
> haven't seen the payload; and by the time you're seeing the payload,
> your only options are to accept, deny, or defer for *all* the RCPT
> which you had accepted.

The latter.

> Then you need to be able to recognise the
> same mail when it comes around again later.

Just enforce splitting at RCPT time for all mails from the same
recipient (or IP address) for the next day or so.

> > So in the common case, you accept messages with multiple deliveries just
> > as you did before. It's only when the SA score of the offered mail
> > _actually_ makes it ambiguous that you defer it and make the sender
> > submit for each recipient individually.
>
> Can you spell out how you would aim to implement that?

Only vaguely.

Keep two ACL variables, set at RCPT time -- the maximum and minimum
thresholds. After DATA compare the SA score. If it's below the minimum,
accept. If it's above the maximum, reject. If it's in the middle, add
the sender address to the "split at RCPT time" database and defer.

If you get a MAIL FROM an address in the "split at RCPT time" database,
give temporary rejections for any recipients whose threshold isn't
precisely equal to the threshold of the first accepted recipient.

Not actually sure if you'd want to do it on MAIL FROM, or on IP address,
or maybe on both. Probably MAIL FROM though.

--
dwmw2