[Dovecot] Why : dovecot_destination_recipient_limit = 1 ?

[Tom Hendrikx]

Koenraad Lelong wrote:
> Markus Schönhaber schreef:
>> Koenraad Lelong:
>>
>>> I'm trying to activate sieve. In all tutorials I have seen I need to
>>> set dovecot_destination_recipient_limit = 1 in Postfix's main.cf. Can
>>> anyone explain why ?
>>> I like to know because when I set this and the dovecot transport in
>>> Postfix, I'm having problems when aliasses are used that map to
>>> different recipients, i.e. info at ... results in user1 at ..., user2 at ...,
>>> etc. The problems are an error from Postfix :
>>> Oct 30 09:25:19 lace3 postfix/pipe[19729]: 8A77E2D5B5B:
>>> to=<some.body at some.where.org>, relay=dovecot, delay=2390,
>>> delays=2390/0.04/0/0.01, dsn=4.3.5, status=deferred (mail system
>>> configuration error)
>>> Oct 30 09:25:19 lace3 postfix/pipe[19729]: warning: pipe flag `D'
>>> requires dovecot_destination_recipient_limit = 1
>>
>> Well, the last message says it all: you've instructed postifx' pipe to
>> add a "Delivered-To" header field to the message. And this obviously
>> can't work when delivering one message to multiple recipients in one
>> pass.
>> See also:
>> http://www.postfix.org/pipe.8.html
>>
> Thanks for your response, Markus.
> Am I to conclude that what I'm trying to do is impossible then, with
> dovecot ?
> I would like to enable sieve on a system where I have aliasses which
> point to multiple recipients.
> For some reason dovecot needs the DRhu flags. The D flag needs
> dovecot_destination_recipient_limit=1 which prevents those multiple
> recipients.
>
> Or am I missing something ?

I'm no postfix guru, but wouldn't those aliases be processed before
interaction with dovecot/deliver, and then multiple deliveries will be
triggered by postfix?
Everything you are configuring is within postfix, so i'm quite sure that
it'll tell what will go wrong when you run into issues when you
configure something 'impossible' with it.

> If I would remove the D-flag, how likely it is to get a loop ?
> Unfortunately I don't have a test-system at the moment.
> 

You could always create a separate test transport and tell postfix to
use that one for a specific test domain...

Regards,
	Tom