Markus Stumpf <maex-lists-spam-ietf-asrg(_at_)Space(_dot_)Net> wrote:
3) You need the hardware/software capable of doing the blocking, so this
is also a cost factor.
Nonsense.
Then the recipient has to do that blocking. Why offload costs from
the sender to the recipient?
I admit it's a great business model for ISP's: Send gigabytes of
crap onto the backbone, because it's cheaper to let someone else deal
with it, than to fix your own network.
The problem is that spammers have exactly the same business model,
and we already know it's unethical.
5) With MTA MARK I as a receiver know what the intention of the
maintainer of the IP space is. With a port 25 block not being there I
don't know if it is on purpose or if it is a mistake.
Publication of site policy is definitely a good thing.
6) If it can be solved with port 25 filtering this would be great. But
the technique to do it is there for years. Why is spam still a problem?
Because of the people who DON'T block port 25. Moving to MTAMark
will have the same deployment issues.
Alan DeKok.
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