Dovecot quota do not match mail directory size

Hi,
Lately, I get complaints from people that use our ISPConfig mailserver (v 3.2.9p1) that although they deleted mails from their mailbox, new incoming mail is still refused. I'm not sure, but it seems to be only happening with users who've already hit the quota limit.
Todays example:
11:11 User sends me a message that new mail does not arrive.
14:30 (It's weekend) I check why. I assume he cleaned out his over-quota mailbox before he send me a mail, because when I check the directory it is down to 6,5G and the user as a 7G quotum. ISPConfig still shows 100% full for this user.
Mail should arrive now, so I send a test message. This bounces with message:
Quota exceeded (mailbox for user is full)
When I run doveadm quota recalc -A, this seems to solve the problem. ISPConfig now shows 93% and the second test mail I send is accepted.
So recalculating the quota manually seems to work, but Dovecot should do this when new mail arrives, right?

Has anyone seen similar problems before?

Could this be a misconfiguration in dovecot? My installation has been upgraded from a very ancient ISPConfig with a stone-age Debian and Courier mail to where we are now, so maybe some configuration file has been missed.

 

This is dovecot.conf

Code:

# Do not change this file, as changes will be overwritten by any ISPConfig update.
# Put your custom settings in /usr/local/ispconfig/server/conf-custom/install/dovecot_custom.conf.master.
# To start using those changes, do a force upgrade and let it reconfigure your services. (ispconfig_update.sh --force)
listen = *,[::]
protocols = imap pop3 lmtp
auth_mechanisms = plain login
disable_plaintext_auth = no
log_timestamp = "%Y-%m-%d %H:%M:%S "
mail_privileged_group = vmail
ssl_cert = </etc/postfix/smtpd.cert
ssl_key = </etc/postfix/smtpd.key
ssl_dh = </etc/dovecot/dh.pem
ssl_min_protocol = TLSv1.2
ssl_cipher_list = ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384
ssl_prefer_server_ciphers = no
mail_max_userip_connections = 100
mail_plugins = quota
passdb {
  args = /etc/dovecot/dovecot-sql.conf
  driver = sql
}
userdb {
  driver = prefetch
}
userdb {
  args = /etc/dovecot/dovecot-sql.conf
  driver = sql
}
plugin {
  quota = dict:user::file:/var/vmail/%d/%n/.quotausage

  # no longer needed, as 'sieve' is in userdb extra fields:
  sieve=/var/vmail/%d/%n/.sieve

  sieve_before=/var/vmail/%d/%n/.ispconfig-before.sieve
  sieve_after=/var/vmail/%d/%n/.ispconfig.sieve
  sieve_max_script_size = 2M
  sieve_max_actions = 100
  sieve_max_redirects = 25
}
service auth {
  unix_listener /var/spool/postfix/private/auth {
    group = postfix
    mode = 0660
    user = postfix
  }
  unix_listener auth-userdb {
    group = vmail
    mode = 0600
    user = vmail
  }
  user = root
}
service lmtp {
  unix_listener /var/spool/postfix/private/dovecot-lmtp {
   group = postfix
   mode = 0600
   user = postfix
   # For higher volume sites, it may be desirable to increase the number of active listener processes.
   # A range of 5 to 20 is probably good for most sites
#   process_min_avail = 5
  }
}
lmtp_rcpt_check_quota = yes
service imap-login {
  client_limit = 1000
  process_limit = 512
}
protocol imap {
  mail_plugins = $mail_plugins quota imap_quota
  auth_verbose = yes
}
protocol pop3 {
  pop3_uidl_format = %08Xu%08Xv
  mail_plugins = $mail_plugins quota
  auth_verbose = yes
}
protocol lda {
postmaster_address = [email protected]
  mail_plugins = $mail_plugins sieve quota
}
protocol lmtp {
postmaster_address = [email protected]
  mail_plugins = $mail_plugins quota sieve
}

service stats {
    unix_listener stats-reader {
        user = vmail
        group = vmail
        mode = 0660
    }

    unix_listener stats-writer {
        user = vmail
        group = vmail
        mode = 0660
    }
}

service quota-status {
  executable = quota-status -p postfix
  unix_listener /var/spool/postfix/private/quota-status {
    group = postfix
    mode = 0660
    user = postfix
  }
  client_limit = 1
}
plugin {
  quota_status_success = DUNNO
  quota_status_nouser = DUNNO
  quota_status_overquota = "552 5.2.2 Mailbox is full"
}

imap_capability=+SPECIAL-USE XLIST
namespace inbox {
  inbox = yes
  separator = .
  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
  }
}

!include_try conf.d/99-ispconfig-custom-config.conf

And this is 99-ispconfig-custom-config.conf:

Code:

#
ssl_cert = </etc/postfix/smtpd.cert
ssl_key = </etc/postfix/smtpd.key

protocol imap {
  mail_plugins = imap_sieve
}

plugin {
  sieve_plugins = sieve_imapsieve sieve_extprograms

  # From elsewhere to Spam folder
  imapsieve_mailbox1_name = Junk
  imapsieve_mailbox1_causes = COPY
  imapsieve_mailbox1_before = file:/etc/dovecot/rspamd/rspamd-learn-spam.sieve

  # From Spam folder to elsewhere
  imapsieve_mailbox2_name = *
  imapsieve_mailbox2_from = Junk
  imapsieve_mailbox2_causes = COPY
  imapsieve_mailbox2_before = file:/etc/dovecot/rspamd/rspamd-learn-ham.sieve

  sieve_pipe_bin_dir = /etc/dovecot/rspamd

  sieve_global_extensions = +vnd.dovecot.pipe +vnd.dovecot.environment
}

 

Thanks, I will try that.

 

I didn't see anything bad in the log files until now (a few hours after changing the configuration) so I assume everything still works. No idea why this line was not the default, but as I said, this server has lived through many configuration changes already.

Normally I would like to report back when a problem is solved, but in this case, when it's solved, nobody will complain about not receiving emails after deleting their over-quota mail. So let's consider the problem solved and if not, I'll get back to you.

Thank you for your support!