Re: Comments on draft-melnikov-sieve-external-lists-02.txt

[Robert Burrell Donkin <robertburrelldonkin@xxxxxxxxx>]

On Wed, Jul 22, 2009 at 3:49 PM, Ned Freed<ned.freed@xxxxxxxxxxx> wrote:
>
>
>> >> But the same issues affect section 2.3.  If the list can't be
>> >> enumerated, you can't redirect to it.
>> >>
>> > :list is not a match type in this case, again it is a black box.
>> ...
>> > So I would like to correct your statement. There is no need whatsoever to be
>> > able to enumerate list membership in Sieve in order to redirect.
>> > The only requirement is that whoever does mailing list expansion needs to be
>> > able to do that. Such entity doesn't have to be the Sieve engine.
>
>> Two things:
>> 1. When I say that the list must be enumerable, I don't necessarily
>> mean "by the Sieve engine."  It's possible for the list not to be
>> enumerable at all, even by the list handler.  Examples are where the
>> list stores hashes of email addresses (to preserve privacy, perhaps)
>> and where the list stores mailbox patterns (all members of department
>> Z have email addresses that start with "dz", so the list of department
>> Z members is querieable ("Is X a member?"), but not enumerable).
>
> Exactly so. And by the same token, a list you can redirect to may not
> necessarily be queryable in any other way.

+1

>> 2. Ah, so you're suggesting that the Sieve engine, which knows how to
>> do a redirect, should pass this on to the list handler, which now also
>> has to know how to do a redirect.  I'm not sure that's a good idea,
>> but I could perhaps be convinced.  I'm curious about what Ned thinks
>> here.
>
> Handling redirect :list by throwing the problem over the fence to a list
> processors is an interesting approach. We actallly use a variant of it - the
> sieve machinery performs variouos actions on the messeage but then invokes our
> more general list expansion machinery to get the necessary address list.

i wonder whether the specification would be cleaner and clearer if it
allowed the sieve and list engines to collaborate in executing the
redirection in the most convenient fashion

- robert