Duplicate folder names

[Paulo Matos]

Hi,

I have setup message filtering and for example, I might move a message 
which a given sender to folder special/. This folder is created and 
shows up twice in INBOX/special/ and special/.

They are however exactly the same folder. If I subscribe to one I am 
automatically subscribed to the other and viceversa. Not too happy with 
this configuration.

I have a feeling this is related to namespaces but I am not sure in 
which way to configure things in order to have only INBOX/special but 
not special/.

How can I set this up. My current configuration is:
$ dovecot -n
# 2.2.18: /etc/dovecot/dovecot.conf
# OS: Linux 4.1.0-x86_64-linode59 x86_64 Fedora release 22 (Twenty Two) ext4
auth_debug = yes
auth_mechanisms = plain login digest-md5 cram-md5
auth_verbose = yes
auth_verbose_passwords = yes
default_internal_user = root
imap_client_workarounds = delay-newmail tb-extra-mailbox-sep
mail_debug = yes
mail_location = maildir:/home/vmail/%d/%n/Maildir
maildir_very_dirty_syncs = yes
mbox_write_locks = fcntl
namespace {
   inbox = yes
   location =
   prefix = INBOX.
   separator = .
   type = private
}
namespace inbox {
   location =
   mailbox Drafts {
     special_use = \Drafts
   }
   mailbox Junk {
     special_use = \Junk
   }
   mailbox Sent {
     special_use = \Sent
   }
   mailbox "Sent Messages" {
     special_use = \Sent
   }
   mailbox Trash {
     special_use = \Trash
   }
   prefix =
}
passdb {
   args = /etc/dovecot/dovecot-sql.conf.ext
   driver = sql
}
postmaster_address = pmatos
protocols = imap
quota_full_tempfail = yes
service auth {
   unix_listener /var/spool/postfix/private/auth {
     group = postfix
     mode = 0666
     user = postfix
   }
   unix_listener auth-master {
     mode = 0600
     user = vmail
   }
   user = $default_internal_user
}
ssl = required
ssl_cert = </etc/pki/dovecot/certs/dovecot.pem
ssl_key = </etc/pki/dovecot/private/dovecot.pem
userdb {
   args = uid=5000 gid=5000 home=/home/vmail/%d/%n allow_all_users=yes
   driver = static
}
protocol lda {
   auth_socket_path = /var/run/dovecot/auth-master
   deliver_log_format = msgid=%m: %$
   log_path = /home/vmail/dovecot-deliver.log
}
protocol imap {
   mail_max_userip_connections = 100
}

Regards,
Paulo Matos