duplicate suppression, sieve, loops, redirect and lost email

[Ragnar Sundblad]

--On den 28 augusti 2002 19:12 -0400 Ken Murchison <ken at oceana.com> wrote:

> Quoting Ragnar Sundblad <ragge at nada.kth.se>:
>
> The message in question does not get lost.  It has already been
> delivered to the recipient once.

I'd rather say that it has been delivered to the recipients
broken sieve script once. :-)

> I _am_ curious what a sane reason for redirecting an email
> to one's self is.

None at all, I certainly agree. But it can happen because
a user does it anyway by mistake or because of confusion,
and that shouldn't mean mail gets lost.

>> What I would rather assume would happen is that the email
>> would loop until sendmail (or whatever mta you are using)
>> returns it due to exceeded hop count. Is this not so?
>
> It shouldn't get to this point.

Without duplicate suppression, that is, maybe I should have
added that. Do you still mean that it shouldn't get to that
point?
I can follow the email two rounds through sendmail until,
I believe, the duplicate suppression removes it.


I like to use the duplicate suppression feature, but there
is a small risk that the user, by mistake, does an implicit
discard when he means redirect.

There is also another problem with the current duplicate
suppression approach:
Say someone posts an email to two different lists which
I have both subscribed to, and the lists servers doesn't
change the msgid but only adds some header. With the current
duplicate suppression only one of them will get delivered
to me. If I have a sieve script that sort each list in a
separate mailbox, based on Sender: for example, only one
of them will be put into its mailbox, the other will just
be missing.

I think that a duplicate suppression feature based on
destination mailbox would be a safe way to solve the same
problem as the current does, and still cause no problem
with those two cases.
With that I mean that at the stage when a mail is about
to be added to a mailbox a check would be made if it
already is in there, and only if so it would be
suppressed.

What do you think?

Thanks for your help!

/ragge