{SPAM} Emails Not Bouncing

[Matt Kettler]

At 05:53 PM 5/10/2004, Kevin Spicer wrote:
>And that too only partially solves the problem, as it pushes the problem
>back upstream, which is fine if the only thing upstream happens to be
>the spammer, unfortunately thats rarely the case.  In fact if you use an
>ISP's store and forward facility as a secondary MX theres a good chance
>thats where your rejects will end up!

True, but at least it's a "attempting to do minimal harm" approach as
opposed to "willfully configuring networks in a manner which is maximizing
the problem".

Let's face it, if the destination address isn't deliverable, it's going to
550 anyway, so the secondary MX and/or relay is going to create the problem
anyway.

Also, being joe-job flooded from one open relay sending you a bunch of DSNs
is easy to deal with. Being flooded from thousands of mailservers
generating "spam bounces" is much more difficult.

Hence, 550ing is MUCH better than post-delivery bouncing. It makes the
difference for the joe-job victim between dealing with a single-source or
few source DoS, and a large-number of sources DDoS attack.

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