[Dovecot] emails are not displayed

[Daniel Fischer]

Hello,

i have a problem with some public folders in my testing environment. But 
after the series, here is my konfiguraion:

doveconf -n
# 2.1.7: /etc/dovecot/dovecot.conf
# OS: Linux 3.2.0-3-amd64 x86_64 Debian wheezy/sid
hostname = .........................................
lda_mailbox_autocreate = yes
lda_mailbox_autosubscribe = yes
listen = *
mail_debug = no
mail_gid = 5000
mail_location = maildir:~:INDEX=/var/mail/indexes/%d/%n
mail_plugins = acl
mail_privileged_group = vmail
mail_uid = 5000
managesieve_notify_capability = mailto
managesieve_sieve_capability = fileinto reject envelope 
encoded-character vacation subaddress comparator-i;ascii-numeric 
relational regex imap4flags copy include variables body enotify 
environment mailbox date ihave
namespace {
   list = children
   location = 
maildir:/var/mail/vhosts/%d/public:INDEX=/var/mail/indexes/%d/public:CONTROL=/var/mail/controls/%d/public
   prefix = Public.
   separator = .
   subscriptions = no
   type = public
}
namespace inbox {
   hidden = no
   inbox = yes
   list = yes
   location =
   prefix =
   separator = .
   subscriptions = yes
   type = private
}
passdb {
   args = scheme=CRAM-MD5 username_format=%u 
/var/mail/vhosts/auth.d/%d/shadow
   driver = passwd-file
}
plugin {
   acl = vfile
   antispam_allow_append_to_spam = no
   antispam_backend = pipe
   antispam_pipe_program = /usr/local/bin/sa-learn-pipe.sh
   antispam_pipe_program_notspam_arg = --ham
   antispam_pipe_program_spam_arg = --spam
   antispam_pipe_tmpdir = /tmp
   antispam_spam = Spam
   antispam_trash = Trash
   sieve = /var/mail/vhosts/sieve/users/%d/%n/.dovecot.sieve
   sieve_before = /var/mail/vhosts/sieve/%d/before
   sieve_dir = /var/mail/vhosts/sieve/users/%d/%n
   sieve_global_dir = /var/mail/vhosts/sieve/%d/global
   sieve_user_log = /var/mail/vhosts/sieve/users/%d/%n/.dovecot.sieve.log
}
postmaster_address = postmaster at .....
protocols = " imap lmtp sieve pop3"
service auth {
   unix_listener /var/spool/postfix/private/auth {
     mode = 0666
   }
   unix_listener auth-userdb {
     mode = 0660
     user = vmail
   }
}
service managesieve-login {
   inet_listener sieve {
     port = 4190
   }
}
ssl_cert = </etc/ssl/private/.................................
ssl_key = </etc/ssl/private/.........................
userdb {
   args = username_format=%u /var/mail/vhosts/auth.d/%d/passwd
   driver = passwd-file
}
protocol lmtp {
   mail_plugins = acl sieve
}
protocol lda {
   log_path = /var/log/sieve.log
   mail_plugins = acl sieve
}
protocol imap {
   imap_idle_notify_interval = 24 mins
   mail_plugins = acl imap_acl antispam
}
protocol sieve {
   managesieve_implementation_string = Dovecot Pigeonhole
   managesieve_logout_format = bytes=%i/%o
}

the problem is that any, not all public folder appear empty. if I delete 
the index files, I see the emails again for a while(1-2 hours) until 
they're gone again sometime. The directories change their content not 
for weeks. It is a test environment. but in one of the folders are more 
than 13000 mails (the Faxbox). Currently 3 of 13 folders are affected. I 
thought that it may be due to the size, but it is not the largest 
folders. For normal mail boxes I have not observed this effect.

a3 EXAMINE Public.faxe
* FLAGS (\Answered \Flagged \Deleted \Seen \Draft)
* OK [PERMANENTFLAGS ()] Read-only mailbox.
* 0 EXISTS
* 0 RECENT
* OK [UIDVALIDITY 1349419566] UIDs valid
* OK [UIDNEXT 141737] Predicted next UID
* OK [HIGHESTMODSEQ 5] Highest

Delete indexes....
/var/mail/indexes/........../public# rm -r .faxe/

a3 EXAMINE Public.faxe
* OK [CLOSED] Previous mailbox closed.
* FLAGS (\Answered \Flagged \Deleted \Seen \Draft)
* OK [PERMANENTFLAGS ()] Read-only mailbox.
* 13778 EXISTS
* 0 RECENT
* OK [UIDVALIDITY 1349419566] UIDs valid
* OK [UIDNEXT 141737] Predicted next UID
* OK [NOMODSEQ] No permanent modsequences

i would like to show you log files but i didn't see any error message.

Does Have anyone an idea?

Thanks for comment...

Daniel