[Dovecot] Server-side sieve for client-side copies

[Daniel L. Miller]

Eduardo M KALINOWSKI wrote:
> Daniel L. Miller escreveu:
>> The question:  can Dovecot be configured to support sieve filters on 
>> IMAP (not just SMTP) operations (Eduardo helped me here - so I'll 
>> specifically ask about the APPEND command).
>>
>> If not , I'll make that a feature-request - "Timo, can Dovecot be 
>> modified to support sieve-filters on APPEND operations?".  Failing 
>> that, can some specific operation subsets of sieve be supported on a 
>> cron-like basis?  My understanding is that operations involving 
>> indexes are extremely fast - and that things like sender/recipient 
>> are included in the indexes.  So filters based on sender/recipient 
>> might be possible?
>>
>
> At this moment it can't. And as a matter of fact, I doubt it ever 
> will, because it doesn't really make sense.
>
> I'm no expert in the IMAP protocol, but as far as I understand, the 
> APPEND command is used to store a new mail in a given mailbox. It 
> would not make sense to run a filter to store the message somewhere 
> other than where the client asked when using that command (just to use 
> the specific example).
I never said it was a GOOD idea....but, actually, what's wrong with it?

Once again, an opportunity for me to use my lower mouth.

IMAP is based on supporting relatively high-speed links (not INTENDED 
for dial-up use...).  So mail is (normally) not stored on the 
client-side - and changes made on the server are quickly reflected by 
the client (for LAN use, I normally set my update freq to 1 minute).  
And this is the kind of thing that would be implemented with the user's 
knowledge (presumably) since it's implemented using the user-configured 
sieve filter.  So, without changing the MUA/MTA/IMAP interaction, the 
IMAP server will simply file new messages according to user-set rules.  
Doesn't address the multiple-transfer issue at all, but does provide an 
option for centralized control of message filing.

-- 
Daniel