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Re: Processing after the end of DATA

2010-08-09 23:18:52

ned+ietf-smtp(_at_)mrochek(_dot_)com wrote:
<csg> writes:

As a result, duplicates were such a staggering huge problem. To mitigate
that, Postini computed a SHA-1 hash for every message, and if there was
any evidence that the receiver had sent the 250 OK, but the sender never
got it, the hash was saved in a database. If the sender resent the
message, the proxy (knowing it had already been delivered) quietly ate it.

When that database broke, the customers noticed immediately. The effect
was that significant.

First of all, in the interests of full and proper disclosure, I should mention that this particular trick is patented: US Patent #7080123. (I'm the author, but Oracle owns the patent.)


Dupe checking method was an essential design requirement since the 80s.

Every Fidonet Mailer since the 80s and basically all online hosting systems, including Wildcat! all had dupe checking since the 80s.

This is a yet another case of a frivolous patent based on the new 1996 Time Line where the existing methods and technology pre 1996 could not be patent was now open to patentability. I seen it all the time and of course, it doesn't apply to companies and organizations that have used these simple methods as normal engineering requirement - Markus RULES!

Dupe checking was an essential SOFTWARE requirement in network topologies where mail dupes was an extremely high occurrence. It wasn't an exception but an every minute expectation.

Fidonet use the network control lines called SEEN-BY lines which is technologically the same as used today by he NNTP PATH line with bang domain addresses. The hidden SEEN-BY lines recorded every node touching the message as it passed thru the network. When the growth of SEEN-BY lines got too large, Tiny SEEN-BY lines were introduced to reduced the syntax recording by COUNTRY, REGIONS or ZONES, NETs with ZONES and NODES within NETS.

With the advent of 822, the Message-ID was used at the LOCAL HOST level, but that was not alway reliable so a local HASH was recorded and there was never any retransmitted DUPES allowed. The DUPE system was generic at the back end so it didn't matter what network the mail come from: Fidonet, UUCICO, SMTP, QWK, OPX, UTI, etc including as posted by a local user online!

A ridiculous patent - no patent can deny was is technologically fundamental and require for normal operations. DUPE CHECKING was a basic ingredient in ALL mail network software since the annals of time. I can not think of one system worth its salt that did not have a dupe checking concept. What? Are we suppose to stop using was so fundamental in all our software since the 80s?



Hector Santos