Re: [exim] UCEPROTECT Blacklists and why callouts are abusiv…

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Author: Stuart Gall
Date:  
To: UCEPROTECT-Network Blacklistmaster of the day
CC: exim-users
Subject: Re: [exim] UCEPROTECT Blacklists and why callouts are abusive

On 17 Oct 2006, at 14:41, UCEPROTECT-Network Blacklistmaster of the
day wrote:

> As we explained on our website, we consider callouts abusive,
> because they
> can make your system part of an ddos against others.
>
> If someone claimes to be you@yourdomain and sends out some million
> spammails
>
> you will get a real feeling, why you should not use callouts.


This is a self defeating argument. If only a few "rouge" sites are
doing sender callouts then no harm is done.
If on the other hand most people are doing sender callouts then your
list is going to get poisoned very quickly.
Unless you believe you can persuade the millions of sites to stop
doing callouts.

>
> Ok your system will have to deal with tons of bounces, but
> additional with
> all those lamerz using sender callouts.


well if you dont do a callout and for whatever reason (secondry mail
server defer for example)
the DSN gets frozen.
Then on most systems it will auto thaw and retry delivery of the DSN.
So that will be at least twice the bandwidth compared to doing callouts.

>
> The problem is not that ONE connecction which you are doing. The
> problem is,
> that you and millions of others
> are trying to verify one address, which leads to a ddos against the
> targeted
> system.
>
> This is the reason why we are blacklisting anyone probing spamtraps
> of the
> project.
>
> The only difference between verifyers and for e.g. TMDA-Abusers is
> that no
> real mail is sent by verifiers.
>
> Anyone using sender callouts shows that he is selfish and it does
> not matter to him, to be part of a ddos against third parties.
>


That is a rather extreme attitude. Callouts is a marginal activity at
worse. The question is do sender callouts cause more problems to
spammers or to sysadmins. IMO they cause vastly more problems for the
spammers than they do for sysadmins.


>
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