[Dovecot] Sieve and LDA

[Mark E. Mallett]

On Wed, Jan 31, 2007 at 08:12:16AM +0100, Steffen Kaiser wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> On Tue, 30 Jan 2007, Vincent Bernat wrote:
> 
> >>>,----
> >>>| 2.10.3. Message Uniqueness in a Mailbox
> >>>|
> >>>|
> >>>|    Implementations SHOULD NOT deliver a message to the same folder more
> >>>|    than once, even if a script explicitly asks for a message to be
> >>>|    written to a mailbox twice.
> >>>|
> >>>|    The test for equality of two messages is implementation-defined.
> >>>|
> >>>|    If a script asks for a message to be written to a mailbox twice, it
> >>>|    MUST NOT be treated as an error.
> >>>`----
n> 
> >Well, with a single invocation, the sentence "The test for equality of
> >two messages is implementation-defined." is a non-sense since messages
> >cannot be  modified. This  is why I  think that the  prohibition spans
> >multiple script invocations.

Ah..  I can see why you read it that way, now.  And indeed that may be
the way it was meant to be read, given the subsection heading and all.
But there is no direct connection between the SHOULD NOT and the
"equality of two messages" phrase.  Still:


> Messages spooled into a mailbox may be immutable, but the same message may 
> take different paths to arrive one particular mailbox, say, through 
> different mailing lists or recipients, remailed or forwarded. I would 
> _not_ like to see these duplicates discarded.

I agree there.  I would not like an implementation to decide, on its
own, to favor one separate delivery over another.  I think that it
(de-duplication across multiple deliveries) is a very useful feature
that could be offered and enabled by the user, but not one I'd like to
see happen automatically.

mm