Re: [exim] Opt-In Spam rbl filtering in exim 3

On Mon, 14 Feb 2005, Steve Drees wrote:

(without attribution, but presumably quoting peter@??? ?)
>
> > Thanks for publishing this. But unfortunately, it's a very good
> > example of how to implement accept-then-bounce spam filtering, which
> > is very bad practice indeed.
> >
> > You shouldn't do this. You certainly shouldn't encourage other people
> > to. Reject unwanted mail at SMTP time.
>
> The rejection is based on inclusing in an RBL.

That's irrelevant to the substantive issue. You are being called on
qute a different point.

> Not all of these inclusions are truly unwanted email. So, the
> dilemna becomes how do I allow my customers to choose to not receive
> these messages while still ensuring that no legitimate email is
> lost?

Let them receive mail into a spam folder, which they occasionally
check for possible bona fide mail before tossing the rest.

> I'd love to be able to do this with a customized reject at SMTP time
> but I think exim v3 lacks the facility to do this.

So stop using that antique. Simple as that.

It was a fine mailer in its day, but that day has definitively passed.
Its own author will tell you as much - am I right, Philip?

Once you have accepted a mail item, it is TOO LATE to go bouncing it
to its apparent envelope sender, under present email conditions. That
cannot be emphasised too strongly. If you do it despite the warnings,
you're going to land up in backscatter blacklists, and then you'll
find yourself unable to send *genuine* non-delivery reports.