Re: [exim] support for domainkeys

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Author: Alan J. Flavell
Date:  
To: Exim User's Mailing List
Subject: Re: [exim] support for domainkeys
On Tue, 28 Sep 2004, Greg A. Woods wrote:

> In the many months I was under attack earlier this year there was only
> ever one single lone (successful) attempt by any other postmaster to
> contact me and ask me if there was a problem; and despite my sending of
> notification of bogus bounces to many hundreds of postmasters the best I
> ever got back was sympathy for the borked nature of their software and
> the inability of their vendor to make even the most basic recipient
> verification available.


Er, yes. Sympathise.

So what's to do about all these .ru MTAs that are sending us bogus
bounces for spams which counterfeited one of our domains as sender?

I'd like to blacklist the lot of them, but I fear that some of them
have bona fide mail traffic with some of our users.

Perhaps it's time to create a new blacklist of MTAs from which we
reject bounces, while accepting otherwise-valid mails with non-null
envelope senders. I don't really *want* to do that (since it clearly
impairs the reliability of mail), but I'm getting heartily sick of
dealing with several bounces per hour that are obviously classifiable
as [collateral spam / backscatter / ricochet / call-it-what-you-will]
but so diverse that they're impossible to spot by any codifiable rule.

(I'm already refusing bounces which quote received headers showing
that the idiots accepted mail from some faker who presented our own
domain or IP address in their HELO, without any excuse for doing so.
But that's not enough to reduce the flow below nuisance level.)

> The people who are lame enough to use such broken software in the first
> place are either too ignorant to figure out what's wrong or else too
> lazy to do anything about it.


In this case, it also seems necessary to speak Russian to communicate
with them. Some of our users do that anyway (hi Aleks), but they're
not part of the postmastering cabal (TINC! SCNR).