Dovecot and recipient_delimiter

[J. Echter]

Hi,

we're using thunderbird as our client, it has the functionality to sort 
spamassassin tagged mails in a folder called 'Junk'.

I have this folder on my dovecot server and i'd like to use the 
recipient_delimiter feature to get my spam/junk mails directly to this 
folder.

what i have done yet:

dovecot.conf:

plugin {
   recipient_delimiter = +
}

postfix: master.cf

dovecot   unix  -       n       n       -       -       pipe
    flags=DRhu user=vmail:vmail null_sender= 
argv=/usr/libexec/dovecot/deliver -f ${sender} -d ${user}@${nexthop} -e 
-m ${extension}

postfix: main.cf

recipient_delimiter = +


what i get:

Apr 14 13:46:50 mule postfix/pickup[22664]: 71ED53C05EE: uid=0 
from=<testuser at testdomain.test>
Apr 14 13:46:50 mule postfix/cleanup[1408]: 71ED53C05EE: 
message-id=<552cfe2a.tR3wZK7y16RgA548%testuser at testdomain.test>
Apr 14 13:46:50 mule postfix/qmgr[12559]: 71ED53C05EE: 
from=<testuser at testdomain.test>, size=465, nrcpt=2 (queue active)
Apr 14 13:46:50 mule dovecot: lda(testuser at testdomain.test): 
msgid=<552cfe2a.tR3wZK7y16RgA548%testuser at testdomain.test>: save failed 
to junk: Mailbox doesn't exist: junk
Apr 14 13:46:50 mule dovecot: lda(testuser at testdomain.test): 
msgid=<552cfe2a.tR3wZK7y16RgA548%testuser at testdomain.test>: saved mail 
to INBOX
Apr 14 13:46:50 mule postfix/pipe[10898]: 71ED53C05EE: 
to=<testuser+Junk at testdomain.test>, relay=dovecot, delay=0.04, 
delays=0.02/0/0/0.02, dsn=2.0.0, status=sent (delivered via dovecot service)
Apr 14 13:46:50 mule postfix/qmgr[12559]: 71ED53C05EE: removed

here is my complete dovecot -n output:

  dovecot -n
# 2.0.9: /etc/dovecot/dovecot.conf
# OS: Linux 2.6.32-504.12.2.el6.x86_64 x86_64 CentOS release 6.6 (Final) 
ext4
auth_cache_negative_ttl = 0
auth_cache_size = 50 M
auth_verbose = yes
base_dir = /var/run/dovecot/
imap_id_log = *
imap_id_send = *
log_timestamp = "%Y-%m-%d %H:%M:%S "
login_log_format_elements = user=<%u> method=%m rip=%r lip=%l mpid=%e %c %k
mail_gid = 5000
mail_home = /DATEN/vmail/%d/%n
mail_location = maildir:/DATEN/vmail/%d/%n/mail/
mail_plugins = " zlib"
mail_uid = 5000
managesieve_notify_capability = mailto
managesieve_sieve_capability = fileinto reject envelope 
encoded-character vacation subaddress comparator-i;ascii-numeric 
relational regex imap4flags copy include variables body enotify 
environment mailbox date ihave
passdb {
   args = /etc/dovecot/dovecot-ldap.conf
   driver = ldap
}
plugin {
   autocreate = Junk
   autosubscribe = Junk
   recipient_delimiter = +
   sieve = /DATEN/vmail/%d/%n/.dovecot.sieve
   sieve_dir = /DATEN/vmail/%d/%n/sieve
   zlib_save = gz
   zlib_save_level = 6
}
protocols = sieve imap
service auth {
   unix_listener /var/spool/postfix/private/auth {
     group = postfix
     mode = 0660
     user = postfix
   }
   unix_listener auth-userdb {
     group = vmail
     mode = 0660
     user = vmail
   }
   user = root
}
service imap-login {
   chroot = login
   executable = /usr/libexec/dovecot/imap-login
   inet_listener imap {
     port = 0
   }
   process_min_avail = 4
   user = dovecot
}
service imap {
   executable = /usr/libexec/dovecot/imap
}
service managesieve-login {
   chroot = login
   user = dovecot
}
service pop3-login {
   chroot = login
   user = dovecot
}
ssl = required
ssl_cert = </shared/config/dovecot/certs/dovecot.pem
ssl_cipher_list = ALL:!LOW:!SSLv2:!EXP:!aNULL:!EXPORT
ssl_key = </shared/config/dovecot/private/dovecot.pem
userdb {
   args = /etc/dovecot/dovecot-ldap.conf
   driver = ldap
}
valid_chroot_dirs = /var/spool/vmail
protocol lda {
   mail_plugins = sieve
   postmaster_address = postmaster
}

any hints on what i do wrong here?

thanks

juergen