--On 25 June 2010 13:56:12 +0100 Ron White <[email protected]> wrote:
> On Fri, 2010-06-25 at 11:28 +0100, Ian Eiloart wrote: >> --On 24 June 2010 09:43:40 +0000 Kebba Foon <[email protected]> wrote: >> >> > >> > Backscatterer - Why it is abusive and how to stop your system doing so >> > >> > Email servers should be configured to provide Non-Delivery Reports >> > (bounces) to local users only. >> > Unacceptable email from anywhere else should be rejected. >> > >> >> This is silly advice. It should be quite acceptable to bounce email that >> has an SPF pass, or that has a valid DKIM signature (provided the return >> path domain matches a signed From header domain). In both cases, if >> you're creating collateral spam, then that's the fault of the domain >> operator. >> > There is probably a bit of a translation issue there as backscatter.org > is part of Dirk & Claus 'UCEProtect' stable of blocklists. > > My personal opinion is you should never accept mail that you cannot > deliver to a user and in such a scenario it should be rejected at SMTP > time - not after a 250 is given and (any/the) MTA decides it does not > want it for whatever reason. Exim is very flexible and its brilliant > ACL's can pretty much reduce backscatter to zero if configured > correctly. Well, the backscatter issue means that we have no choice but to try to do that. But that's a bad thing. It would be a much better world in which we were able to accept such messages, and then generate a bounce. Why? Because bounce messages have the potential to be more user-friendly. I believe that with improved email authentication (SPF, DKIM, etc), we'll one day be able to revive the bounce message. -- Ian Eiloart IT Services, University of Sussex 01273-873148 x3148 For new support requests, see http://www.sussex.ac.uk/its/help/ -- ## List details at http://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
