Re: IPv6 email reflector

[Philip Homburg <pch-v6ops@u-1.phicoh.com>]

In your letter dated Wed, 14 Jul 2010 09:54:58 +0200 you wrote:
>> Well, actually as far as I could see the email one gets back doesn't
>> really contain any subject/body from the original email, so the use for
>> spammers is limited (?).
>
>It is another mail in your mailbox that should not be there in the first
>place.
>
>Same issue as with DSNs, mails should be rejected at DATA time so that
>the sending SMTP server has the handle the issue, not by the receiving
>SMTP server which then accepts it and then decided it doesn't want it.

I think it is better use of terminology to distinguish between spam and
back-scatter.

The reason is that spam is done on purpose, and back-scatter is incidental.
And that leads to a different security analysis.

So I can imagine that with some precautions, like rate limiting the output of
the reflector to prevent DoS attacks, and some requirements on the request
(to prevent back-scatter) the reflector may be quite safe to run.