ietf-smtp
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Re: NDNs considered harmful

2010-08-12 10:16:36

Not doing what is not expected works. IMO, most of the problem can been observed with setups that accept mail first or are less aggressive at SMTP filtering - the Dynamic vs POST SMTP setup. They are normally put into the position to thinking of and/or implementing discarding of mail as a general solution. Even if 95% of the connections are bad people, rejecting 80%, 90% of that at SMTP is a major spam reduction.

The behavior is akin to blindly allowing thousands of people into your Disco, then going around the bar and disco floor throwing out the people you don't want. Filtering them at the door seems to work for the Disco industry.

In my opinion, in the past, larger volume systems had to accept mail first for post smtp mail processing because it was the only way they could scale the volume.

Today, that has changed. Even the AOL, YAHOO, and many of the older large email systems have moved more to SMTP level filtering. Smaller volume systems long enjoyed SMTP level filtering because it was feasible for them to do.


Rosenwald, Jordan wrote:
True statement, but that means the senders of the other 5% are now left
in the dark as to what happened to their mail.
Is there a proposed solution to that?



-----Original Message-----
From: owner-ietf-smtp(_at_)mail(_dot_)imc(_dot_)org 
[mailto:owner-ietf-smtp(_at_)mail(_dot_)imc(_dot_)org]
On Behalf Of John Levine
Sent: Wednesday, August 11, 2010 5:51 PM
To: ietf-smtp(_at_)imc(_dot_)org
Cc: msk(_at_)cloudmark(_dot_)com
Subject: Re: NDNs considered harmful


I note, again fwiw, that I've been trying to get various advocates
for a ban (or near-ban) on NDNs to write that separate document and
propose a specific model at regular intervals since well before
2821 was completed.

I'm new to that particular topic.  Can you explain its motivation or
point me to a discussion thread that lays it out so I can get some
context?

Nothing surprising -- on today's Internet where 95% of mail is spam
and essentially all the spam has forged return addresses, no matter
how careful you are, most of your NDNs will be blowback to people who
didn't send the mail.

R's,
John






--
Sincerely

Hector Santos
http://www.santronics.com