Dovecot als IMAP-Server für Thunderbird, Outlook 2010 und Outlook 2013

[dodge]

Hallo,
ich konfiguriere gerade einen Dovecot-Mailserver um mit IMAP auf die E-Mails zugreifen zu können. Nun entsteht jedoch das "Ordner-Chaos" beim Verbinden von Outlook 2010 und Thunderbird. D.h. Outlook erstellt für sich die Ordner, die es braucht (Gesendete Elemente, Spam-E-Mail, ...) und Thunderbird erstellt noch einmal (Sent, Spam, ...) die entsprechenden Ordner.

In der /etc/dovecot/conf.d/15-mailboxes.conf habe ich aktuell folgende Konfiguration auf einem Debian:

##
## Mailbox definitions
##

# NOTE: Assumes "namespace inbox" has been defined in 10-mail.conf.
namespace inbox {

  #mailbox name {
    # auto=create will automatically create this mailbox.
    # auto=subscribe will both create and subscribe to the mailbox.
    #auto = no

    # Space separated list of IMAP SPECIAL-USE attributes as specified by
    # RFC 6154: \All \Archive \Drafts \Flagged \Junk \Sent \Trash
    #special_use =
  #}

  # These mailboxes are widely used and could perhaps be created automatically:
#  mailbox Drafts {
#    special_use = \Drafts
#  }
#  mailbox Junk {
#    special_use = \Junk
#  }
#  mailbox Trash {
#    special_use = \Trash
#  }

  # For \Sent mailboxes there are two widely used names. We'll mark both of
  # them as \Sent. User typically deletes one of them if duplicates are created.
#  mailbox Sent {
#    special_use = \Sent
#  }
#  mailbox "Sent Messages" {
#    special_use = \Sent
#  }

  # If you have a virtual "All messages" mailbox:
  #mailbox virtual/All {
  #  special_use = \All
  #}

  # If you have a virtual "Flagged" mailbox:
  #mailbox virtual/Flagged {
  #  special_use = \Flagged
  #}
mailbox Drafts {
                special_use = \Drafts
                auto=subscribe
        }
        mailbox Junk {
                special_use = \Junk
                auto=subscribe
        }
        mailbox Trash {
                special_use = \Trash
                auto=subscribe
        }
        mailbox Sent {
                special_use = \Sent
                auto=subscribe
        }
        mailbox "Sent Messages" {
                special_use = \Sent
        }
        mailbox Archive {
                special_use = \Archive
                auto=no
        }
        mailbox "Archives" {
                special_use = \Archive
                auto=subscribe
        }
}

Was ist falsch?