[Dovecot] Clients show .subscriptions folder

[Mark Sapiro]

Since upgrading from dovecot-2.1.rc1 to dovecot-2.1.rc3, some clients
are showing a .subscriptions file in the user's mbox path as a folder.

Some clients such as T'bird on Mac OS X create this file listing
subscribed mbox files. Other clients such as T'bird on Windows XP show
this file as a folder in the folder list even though it cannot be
accessed as a folder (dovecot returns CANNOT Mailbox is not a valid
mbox file).

I think this may be a result of uncommenting the inbox namespace in
conf.d/10-mail.conf
<http://hg.dovecot.org/dovecot-2.1/rev/2c8d39467f21>.

Is there a way to supress exposing this file to clients that don't use
it?

# dovecot -n
# 2.1.rc3: /usr/local/etc/dovecot/dovecot.conf
# OS: Linux 2.6.18-8.1.14.el5 i686 CentOS release 5 (Final)
auth_mechanisms = plain apop login
auth_worker_max_count = 5
mail_location = mbox:~/Mail:INBOX=/var/spool/mail/%u
mail_privileged_group = mail
mbox_write_locks = fcntl dotlock
namespace inbox {
  inbox = yes
  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 = /usr/local/etc/dovecot.passwd
  driver = passwd-file
}
passdb {
  driver = pam
}
protocols = imap pop3
service auth {
  unix_listener /var/spool/postfix/private/auth {
    mode = 0666
  }
}
ssl_cert = </etc/httpd/conf/ssl/combined.crt
ssl_key = </etc/httpd/conf/ssl/www.grizz.org.key
userdb {
  driver = passwd
}
protocol imap {
  mail_max_userip_connections = 30
}
#
-- 
Mark Sapiro <mark at msapiro.net>        The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan