[Dovecot] Problem: dovecot-lda doesn't auto-create folders

[Karim 'Kasi Mir' Senoucci]

Hello everyone,
I recently updated to dovecot 2.0.19 (in fact, I updated the whole 
system to Ubuntu 12.04 LTS, I am using the dovecot from the Ubuntu 
packages) and just today found out that the dovecot-lda for some reason 
doesn't auto-create missing folders anymore as it did with my old 
installation (1.0.10).

I have a "system users" layout and send my mails through a user-specific 
procmail filter. Every delivery in those filters is done via dovecot-lda 
using a line list this:

> |$DELIVER -d archive -m lists.hylafax-`date "+%Y%m"`

where $DELIVER is set to

> DELIVER="/usr/bin/sudo /usr/lib/dovecot/dovecot-lda"

(I use the sudo because some of the procmail lines deliver the mail to 
folders in a different user's mailbox.)

This works fine for all users, unless the mail folder to be delivered to 
doesn't exist yet. Here's an example of such a delivery attempt:

> Oct 01 10:57:09 lda: Debug: auth input: archive 
> system_groups_user=archive uid=1002 gid=1002 home=/home/archive
> Oct 01 10:57:09 lda(archive): Debug: Effective uid=1002, gid=1002, 
> home=/home/archive
> Oct 01 10:57:09 lda(archive): Debug: Namespace : type=private, 
> prefix=, sep=/, inbox=yes, hidden=no, list=yes, subscriptions=yes 
> location=maildir:/home/archive/Maildir
> Oct 01 10:57:09 lda(archive): Debug: maildir++: 
> root=/home/archive/Maildir, index=, control=, 
> inbox=/home/archive/Maildir, alt=
> Oct 01 10:57:09 lda(archive): Debug: none: root=, index=, control=, 
> inbox=, alt=
> Oct 01 10:57:09 lda(archive): Debug: Destination address: xxx at xxxx.de 
> (source: user at hostname)
> Oct 01 10:57:09 lda(archive): Debug: Namespace : 
> /home/archive/Maildir/.lists.hylafax-201210 doesn't exist yet, using 
> default permissions
> Oct 01 10:57:09 lda(archive): Debug: Namespace : Using permissions 
> from /home/archive/Maildir: mode=0755 gid=-1
> Oct 01 10:57:09 lda(archive): Debug: Namespace : 
> /home/archive/Maildir/.lists.hylafax-201210 doesn't exist yet, using 
> default permissions
> Oct 01 10:57:09 lda(archive): Debug: Namespace : Using permissions 
> from /home/archive/Maildir: mode=0755 gid=-1
> Oct 01 10:57:09 lda(archive): Info: 
> msgid=<201210010954.02813.hylafax_resp at earthshod.co.uk>: save failed 
> to open mailbox lists.hylafax-201210: Mailbox doesn't exist: 
> lists.hylafax-201210
> Oct 01 10:57:09 lda(archive): Info: 
> msgid=<201210010954.02813.hylafax_resp at earthshod.co.uk>: saved mail to 
> INBOX

Can anyone tell me what goes wrong here and how to fix it? From what I 
could find out dovecot-lda should auto-create those mailbox folders, but 
somehow it doesn't. Any help is appreciated.

Thanks in advance
Kasi Mir