[Dovecot] Vacation: Missing file .dovecot.lda-dupes ?

[Tobias Balle-Petersen]

Hello....

I'm using the vacation feature, but the vacation reply is sent when ever 
a mail is received. What I want is, that the reply should only be sent 
one time to each user.

My understanding is, that a list of people who have received the 
vacation message should be stored in the file .dovecot.lda-dupes in the 
users folder. This file is not present in my users fould. I have tried 
creating the file, but this makes no difference.

Any ideas?

Output from dovecot -n:

# 1.0.10: /etc/dovecot/dovecot.conf
log_timestamp: %Y-%m-%d %H:%M:%S
protocols: imaps imap
listen: localhost:143
ssl_listen: *:993
ssl_cert_file: /etc/ssl/certs/XX.crt
ssl_key_file: /etc/ssl/private/XX.key
ssl_key_password: XXXXXXXXXXXXXXXXXXXX
disable_plaintext_auth: no
login_dir: /var/run/dovecot/login
login_executable: /usr/lib/dovecot/imap-login
login_greeting: System ready.
login_process_per_connection: no
valid_chroot_dirs: /home/vmail
mail_extra_groups: mail
mail_location: maildir:/home/vmail/%n/mail:INDEX=/var/indexes/%n
maildir_copy_with_hardlinks: yes
mail_plugins: quota imap_quota trash
imap_client_workarounds: delay-newmail
auth default:
   username_format: %n
   verbose: yes
   debug: yes
   passdb:
     driver: ldap
     args: /etc/dovecot/dovecot-ldap.conf
   userdb:
     driver: ldap
     args: /etc/dovecot/dovecot-ldap.conf
   socket:
     type: listen
     client:
       path: /var/spool/postfix/private/auth-client
       mode: 432
       user: postfix
       group: vmail
     master:
       path: /var/run/dovecot/auth-master
       mode: 432
       user: vmail
       group: vmail
plugin:
   quota: maildir:storage=10485760
   quota2: maildir:user quota
   trash: /etc/dovecot/dovecot-trash.conf
   sieve: /home/vmail/%n/.dovecot.sieve

Thanks,
Tobias