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Re: Bounce/System Notification Address Verification

2005-06-29 04:54:16



--On Wednesday, 29 June, 2005 00:50 -0400 Keith Moore
<moore(_at_)cs(_dot_)utk(_dot_)edu> wrote:

I am not rejecting anything. All I am suggesting is that when
more than  one recipient is to be used for the message, to
generate a separate copy  for each recipient (with only that
recipient listed as the "To") so  there are separate copies
(as would occur with multi-recipient [messages  where each
recipient is in a different domain] at the MTA stage ).

Why should an MTA or MUA bother to do this?  This part of the
SMTP standard has been stable since c. 1980 and it has _never_
required this.
...
spammers have consistently shown themselves to be very
flexible at adapting to far more substantial countermeasures.
and it's much easier for spammers to adapt than for the vast
installed base to adapt.  it is counterproductive to impose
meaningless restrictions on legitimate senders.  in the long
term this only adds complexity and damages transparency of the
mail system without doing anything to discourage spam.

And, of course, going to one-recipient-per-message also vastly
increases total transmission time for messages, especially
moderately long messages, in normal use.  That total
transmission time issue -- let's open a minimal number of TCP
connections and transmit the payload on a target host basis, not
a target user one-- is, of course, why the multiple RCPT
provision was included in the mail specs more than a quarter of
a century ago.

Folks, I don't know how to say this more strongly, but, if we
are willing to wreck the normal and efficient functioning of the
mail system in order to reduce the amount of spam that gets
delivered, there are, well, more efficient ways to wreck the
mail system.

    john




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