On 2014-08-27, Konstantin Boyandin <lists@???> wrote: > Hello,
>
> Could someone suggest better way to prevent Exim backscatter? Exim 4.72
> is in use. There are two solutions considered:
backscatter is bounce notifications sent in response to emails sent to
domains for which you are MX.
> 1. Set up proper ACL to prevent backscatter (verifying the sender before
> doing so)
> 2. Create 'catchall' router, intercepting all unrouteable addresses (I
> think this is better solution).
You should know which addresses ae legal for domains where you are MX.
doing recipient callouts and cut-thru routing are acceptable for
domains where you are MX.
sender verification is basically impossible,
but greylisting, SPF, and DBLs are all options.
> If I need to provide Exim configuration file, please let me know what
> parts I may omit/mangle prior to sending here.
domain, user names, names and IP addresses are fair game.
but to avoid confusion your mangling function should be a
bijection and be applied consistently. try to be obvious.
