Re: [exim] How to avoid generating backscatter?

On Wed, 2007-05-02 at 16:21 +0100, Richard.Hall wrote:
> Hello, hope someone can help with this hypothetical (at the moment)
> situation ...
>
> - spammer sends email to userA@domainA
> - domainA fails to detect that it is spam
> - userA has set up forwarding to userB@domainB
> - domainA attempts to forward email to userB@domainB
> - domainB detects that it is spam, and rejects it (5xx)
> - domainA sees 5xx, generates NDR, attempts to send it to ... oops, you
> guessed, forged sender.
>
> Is there any way for domainA to prevent the generation, or at least the
> transmission, of the NDR? (Other than improving its spam detection
> rates!!)
>
> For bonus points, can domainA hang on to the original email and/or the NDR
> (eg by freezing it/them), for later inspection?

you'll need to use some rewriting, like SRS, on the return-path. you
can then handle bounces to these addresses in any way you like,
including delivering them to BSMTP files for manual handling.

unfortunately, this means your server becomes SPF compliant.
--
Kjetil T.