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Re: Which Spam Block List to use for a network?

On Wed, Jun 23, 2004 at 08:32:17AM +0200, Adrian 'Dagurashibanipal' von Bidder wrote:
> On Wednesday 23 June 2004 03.27, Blu wrote:
> > > > In my server, my policy is to reject mail from hosts which are
> > > > blocking me.
> > [...] blocking mail which cannot be
> > answered blocks a lot of forged sender spam too, something like 80%
> > here, being conservative.
> You did say two different things here.
> I block mail which can't be answered, too, by requiring the send domains 
> to exist. After an upgrade to postfix 2.1 I will consider verifying the 
> user part of sender addresses, too, if greylisting doesn't get the spam 
> down far enough.

Well, if a host blocks mail from me, mail from that host is in fact
unanswerable mail. It is just a subset of mail which can't be answered.

> I've never had my mail rejected by some mailserver, yet, but I don't 
> think I would just block mail from mailservers blocking me - when my 
> block produces false positives, I'm glad if people tell me (the 550 
> message tells them how to contact me by email without being blocked.) 
> So I like to extend the same courtsy to the operator of the other box. 
> As was said in this thread by somebody, it's all about enabling 
> communication, and not about making it impossible. And blocking spam 
> just keeps email a useful medium.

My 550 tells people that it is HIS host which is blocking mail from mine
and that I will accept mail from them as soon they stop blocking me.

I run a number of public service servers and in the past, from the
perspective of an user of a server which blocks mail from mine, the
mails were being blackholed at my host. They never got an answer or even
a bounce. Now, at least they know what is going on and know that the
problem is their side, not mine.

Finally, I keep postmaster always open, a thing that a lot of this happy
blocking servers does not.


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