Re: several messages

[Rich Kulawiec <rsk at gsp.org>]

On Wed, Nov 12, 2008 at 11:33:46AM -0800, Randy Presuhn wrote:
> Huh?  Concrete, real example:  I send a message to an IETF mailing list.
> A list subscriber's ISP rejects the forwarded message.  IETF's mailman
> drops the subscriber, because this has been happened multiple times.
> I can't notify the subscriber, because their ISP also rejects my email.

This is not a DNSBL problem.  This is a problem with the subscriber's ISP,
which is not operating their mail system per de facto best practices --
which include making sure that rejection notices provide an alternate-channel
means of contacting them in order to discuss apparently-erroneous blocking.
There are a sizable number of techniques for doing this; I happen to think
the best ones are quite simple, e.g.:

	reject=550 5.7.1 <fred at example.com>... Mail refused - [201.45.252.2] listed by Spamhaus (http://www.spamhaus.org) - forward this message to nov-13-2008 at example.com if you believe this is a mistake

of course nov-13-2008 at example.com needs to be exempted from the same
blocking and should forward to the postmaster/abuse staff at example.com.

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Date: Thu, 13 Nov 2008 11:56:01 -0500
From: Rich Kulawiec <rsk at gsp.org>
To: ietf at ietf.org
Subject: Re: several messages
Message-ID: <20081113165601.GA2969 at gsp.org>
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On Wed, Nov 12, 2008 at 11:33:46AM -0800, Randy Presuhn wrote:
> Huh?  Concrete, real example:  I send a message to an IETF mailing list.
> A list subscriber's ISP rejects the forwarded message.  IETF's mailman
> drops the subscriber, because this has been happened multiple times.
> I can't notify the subscriber, because their ISP also rejects my email.

This is not a DNSBL problem.  This is a problem with the subscriber's ISP,
which is not operating their mail system per de facto best practices --
which include making sure that rejection notices provide an alternate-channel
means of contacting them in order to discuss apparently-erroneous blocking.
There are a sizable number of techniques for doing this; I happen to think
the best ones are quite simple, e.g.:

	reject=550 5.7.1 <fred at example.com>... Mail refused - [201.45.252.2] listed by Spamhaus (http://www.spamhaus.org) - forward this message to nov-13-2008 at example.com if you believe this is a mistake

of course nov-13-2008 at example.com needs to be exempted from the same
blocking and should forward to the postmaster/abuse staff at example.com.

There are many othmany other ways to accomplish the same thing at minimal effort
and cost; the unifying factor they all share is that recognize that all
anti-spam setups have non-zero FP rates, so it's a good idea to be prepared
to deal with those situations when they arise.

---Rsk
_______________________________________________
Ietf mailing list
Ietf at ietf.org
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er ways to accomplish the same thing at minimal effort
and cost; the unifying factor they all share is that recognize that all
anti-spam setups have non-zero FP rates, so it's a good idea to be prepared
to deal with those situations when they arise.

---Rsk
_______________________________________________
Ietf mailing list
Ietf at ietf.org
https://www.ietf.org/mailman/listinfo/ietf