[Dovecot] Why : dovecot_destination_recipient_limit = 1 ?

[Markus Schönhaber]

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

-- 
Regards
  mks