[Dovecot] quota warning issue

[Alex]

Hello to all,
I'm using version 1.1.11 of dovecot.
I set the quota using the following configuration:

in /etc/dovecot/dovecot.conf

  quota = maildir:%u
  quota_warning = storage=75%% /root/quota-warning.sh 75 %u

in /etc/dovecot/dovecot-sql.conf

user_query = SELECT concat('/var/vmail/', maildir) as home, 
concat('maildir:/var/vmail/', maildir) as mail, 1000 AS uid, 12 AS gid, 
concat('*:storage=', ROUND(quota/1000)) AS quota_rule FROM mailbox WHERE 
username = '%u' AND active = '1'
##
password_query = SELECT username as user, password, 
concat('/var/vmail/', maildir) as home, concat('maildir:/var/vmail/', 
maildir) as mail, 1000 AS uid, 12 AS gid, concat('*:storage=', 
ROUND(quota/1000)) AS quota_rule FROM mailbox WHERE username = '%u' AND 
active = '1'

# 1.1.11: /etc/dovecot/dovecot.conf
# OS: Linux 2.6.25-hardened-r11 x86_64 Gentoo
base_dir: /var/run/dovecot/
log_path: /var/log/mail.log
info_log_path: /var/log/mail.log
protocols: imap imaps pop3 pop3s
listen(default): *:143
listen(imap): *:143
listen(pop3): *:110
ssl_listen(default): *:993
ssl_listen(imap): *:993
ssl_listen(pop3): *:995
disable_plaintext_auth: no
login_dir: /var/run/dovecot//login
login_executable(default): /usr/libexec/dovecot/imap-login
login_executable(imap): /usr/libexec/dovecot/imap-login
login_executable(pop3): /usr/libexec/dovecot/pop3-login
first_valid_uid: 1000
last_valid_uid: 1000
mail_location: maildir:/var/vmail/%d/%u
mail_debug: yes
mail_executable(default): /usr/libexec/dovecot/imap
mail_executable(imap): /usr/libexec/dovecot/imap
mail_executable(pop3): /usr/libexec/dovecot/pop3
mail_plugins(default): quota imap_quota
mail_plugins(imap): quota imap_quota
mail_plugins(pop3): quota
mail_plugin_dir(default): /usr/lib64/dovecot/imap
mail_plugin_dir(imap): /usr/lib64/dovecot/imap
mail_plugin_dir(pop3): /usr/lib64/dovecot/pop3
imap_client_workarounds(default): outlook-idle delay-newmail
imap_client_workarounds(imap): outlook-idle delay-newmail
imap_client_workarounds(pop3):
pop3_uidl_format(default): %08Xu%08Xv
pop3_uidl_format(imap): %08Xu%08Xv
pop3_uidl_format(pop3): %v.%u
pop3_client_workarounds(default):
pop3_client_workarounds(imap):
pop3_client_workarounds(pop3): outlook-no-nuls oe-ns-eoh
auth default:
   user: nobody
   verbose: yes
   passdb:
     driver: sql
     args: /etc/dovecot/dovecot-sql.conf
   userdb:
     driver: sql
     args: /etc/dovecot/dovecot-sql.conf
   userdb:
     driver: prefetch
   socket:
     type: listen
     client:
       path: /var/spool/postfix/private/auth
       mode: 432
       user: postfix
       group: mail
     master:
       path: /var/run/dovecot/auth-master
       mode: 384
       user: vmail
       group: mail
plugin:
   quota: maildir:%u
   quota_warning: storage=75%% /root/quota-warning.sh 75 %u
   sieve: /var/vmail/%d/%n/.dovecot.sieve


The warning is not delivered to users.
In my logs the user quota's percentage is calculated right

dovecot: Feb 15 23:42:33 Info: IMAP(alex at foo.org): Loading modules from 
directory: /usr/lib64/dovecot/imap
dovecot: Feb 15 23:42:33 Info: IMAP(alex at foo.org): Module loaded: 
/usr/lib64/dovecot/imap/lib10_quota_plugin.so
dovecot: Feb 15 23:42:33 Info: IMAP(alex at foo.org): Module loaded: 
/usr/lib64/dovecot/imap/lib11_imap_quota_plugin.so
dovecot: Feb 15 23:42:33 Info: IMAP(alex at foo.org): Effective uid=1000, 
gid=12, home=/var/vmail/foo.org/alex/
dovecot: Feb 15 23:42:33 Info: IMAP(alex at foo.org): Quota root: 
name=alex at foo.org backend=maildir args=
dovecot: Feb 15 23:42:33 Info: IMAP(alex at foo.org): Quota rule: 
root=alex at foo.org mailbox=* bytes=52428800 messages=0
dovecot: Feb 15 23:42:33 Info: imap-login: Login: user=<alex at foo.org>, 
method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, secured
dovecot: Feb 15 23:42:33 Info: IMAP(alex at foo.org): Quota warning: 
bytes=39321600 (75%) messages=0 command=/root/quota-warning.sh 75 
alex at foo.org


but also overcoming the space defined on quota warning, the command is 
not performed.
The command does not contain errors because if performed by cli 
correctly sends the alert.
Any ideas?

Regards.

Alex