[Dovecot] All messages in double in a virtual mailbox.

[François-Xavier Payet]

 Hello,
 I've got some virtual maiboxes that are configured as follows :

 !RealMail.Sent
 RealMail.Sent
   all

 In all those mailboxes, all the messages appears in double. I don't 
 think it's the expected behaviour, but I perhaps missed something.

 Here's my dovecot -n :

 # 1.2.15: /etc/dovecot/dovecot.conf
 # OS: Linux 2.6.32-bpo.5-amd64 x86_64 Debian 5.0.7
 log_timestamp: %Y-%m-%d %H:%M:%S
 protocols: imaps managesieve
 login_dir: /var/run/dovecot/login
 login_executable(default): /usr/lib/dovecot/imap-login
 login_executable(imap): /usr/lib/dovecot/imap-login
 login_executable(managesieve): /usr/lib/dovecot/managesieve-login
 mail_privileged_group: mail
 mbox_write_locks: fcntl dotlock
 mail_executable(default): /usr/lib/dovecot/imap
 mail_executable(imap): /usr/lib/dovecot/imap
 mail_executable(managesieve): /usr/lib/dovecot/managesieve
 mail_plugins(default): virtual
 mail_plugins(imap): virtual
 mail_plugins(managesieve):
 mail_plugin_dir(default): /usr/lib/dovecot/modules/imap
 mail_plugin_dir(imap): /usr/lib/dovecot/modules/imap
 mail_plugin_dir(managesieve): /usr/lib/dovecot/modules/managesieve
 namespace:
   type: private
   separator: .
   location: virtual:/var/vmail/%d/%n/Maildir/virtual
   inbox: yes
   list: yes
   subscriptions: yes
 namespace:
   type: private
   separator: .
   prefix: RealMail.
   location: maildir:/var/vmail/%d/%n/Maildir
   hidden: yes
   list: no
   subscriptions: yes
 lda:
   log_path: /var/vmail/dovecot-deliver.log
   auth_socket_path: /var/run/dovecot/auth-master
   postmaster_address: foux at da-foux-server.tfdn.org
   mail_plugins: sieve virtual
 auth default:
   mechanisms: plain login
   passdb:
     driver: sql
     args: /etc/dovecot/dovecot-sql.conf
   userdb:
     driver: passwd
   userdb:
     driver: static
     args: uid=5000 gid=5000 home=/var/vmail/%d/%n allow_all_users=yes
   socket:
     type: listen
     client:
       path: /var/spool/postfix/private/auth
       mode: 432
       user: postfix
       group: postfix
     master:
       path: /var/run/dovecot/auth-master
       mode: 384
       user: vmail
 plugin:
   sieve: /var/vmail/%d/%n/sieve
   sieve_dir: /var/vmail/%d/%n/.sieve

 Thanks for your help
 François-Xavier Payet