[Dovecot] Why : dovecot_destination_recipient_limit = 1 ?

[Koenraad Lelong]

Hi all,

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. i...@... results in us...@..., us...@..., 
etc. The problems are an error from Postfix :
Oct 30 09:25:19 lace3 postfix/pipe[19729]: 8A77E2D5B5B: 
to=<some.b...@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

Thanks for any info.

Regards,

Koenraad Lelong.