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Re: Sendmail white paper

2005-01-11 08:02:24
Hello!

On Wed, Nov 24, 2004 at 12:25:30PM -0000, Richard Bang wrote:

Sticking to the snail mail analogy IMO only shows that you don't understand
the problem correctly.

If I send snail mail to you, the recipient is what I write on the package.
If the post office redirect it they stick a label on it saying so. The
recipient is no longer the original address. Do you really send snail mail
to your local post office:

To: David
c/o local post office

And ask them to forward it on to you! The first deliver stage doesn't finish
until it reaches the stated address, the post office and all its offices is
just an MX relay. Your actual address is the critical part.

If I send a message to david(_at_)whatever and, when it reaches 
david(_at_)whatever,
its forwarded to david(_at_)anywhere the recipient is no longer the same. It
arrived at its destination (david(_at_)whatever) and YOU david(_at_)whatever 
chose to
send it to a new address (david(_at_)anywhere). I did not send it to
david(_at_)anywhere and any delivery problems between david(_at_)whatever and
david(_at_)anywhere are yours and not mine. Mail that goes from 
david(_at_)whatever to
david(_at_)anywhere should be identified in its envelope as just that and I
should not be responsible for authenticating that I can send from your first
address to your second.

In Germany, when I ask to have my mail redirected after moving, letters
flow like this:

1) original letter. On the envelope, it's stated
   Sender: Some Name
           Some Road 42
           12345 Some Town

   Recipient: Hannah Schroeter
              Old Road 17
              54321 Old Town

2) The letter is posted and directed to the distribution site for zip
   code 54321. There, the redirection (forwarding) list is checked and
   they find, oh, this is forwarded to New Road 15, 23456 New Town.
   They cross the old recipient address and write the new one on it
   (or use some sticky label for that purpose).

   Note that the do *not* replace the Sender, nor hide it!

3) The letter is re-posted and directed to zip code 23456. There the
   local distributor puts it into my new mailbox in New Road 15.

So snail mail forwarding, in Germany, works exactly like legacy .forward
style email forwarding, no sender rewriting involved!

And noone accuses the mail distribution service in Old Town of forgery.

As it's still a letter from Some Name, reachable at Some Road 42 in Some
Town, to me. And *not* a letter from me, Old Road 17..., to me New Road
15... And *not* a letter from (garbled pseudo-name), (garbled
pseudo-street), 54321 Old Town to me. *That* would in fact be
misrepresenting the authorship.

And btw., if for some reason my address in New Road 15, 23456 New Town
isn't reachable, yes, the original sender, Some Name, comes to receive
the return. Yes.

Kind regards,

Hannah.


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