Re: [exim] Exim 4.72: preventing backscatter

On 27.08.2014 17:11, Konstantin Boyandin wrote:
> Hello,
>
> Could someone suggest better way to prevent Exim backscatter? Exim 4.72
> is in use. There are two solutions considered:
>
> 1. Set up proper ACL to prevent backscatter (verifying the sender before
> doing so)
In my definition backscatter is bounces that you receive when somebody
else send crap (virus, phishing, spam, whatever...) using an
email-address at your domain as a sender. Since bounces should not have
a sender, there is no sender to verify.


> 2. Create 'catchall' router, intercepting all unrouteable addresses (I
> think this is better solution).
Don't. You don't have to bother about bounces that are sent to
non-existing recipients.

>
> I couldn't find solutions (configuration snippets) within reasonable
> timeframe. Could someone direct me to some?
I would consider BATV, which allows you do detect bogous bounces.
However, you have to make sure that every email regarding your domain is
in fact send via you mailserver, since you have to tag the outgoing
emails and check for this tag in the bounces.

If your users don't use your servers, BATV won't be an option.


--
CU,
Patrick.