[Dovecot] quota on virtual user / domains ?

[Marko Weber]

Hi there,
got my ago problems working.
now the last step i dont get working , quota for user in virtual 
user/domain setup.

in dovecot.conf  i added =

mail_plugins = antispam quota imap_quota
 plugin {
             user_query = SELECT home, uid, gid, concat('*:storage=', 
quota_bytes, 'B') AS quota_rule FROM users WHERE userid = '%u'
}


on test, the quota dont work. i set in postfixadmin quota 30mb fpr the 
testaccount
and can send more then 40 mb to it by 8x 5mb attachements.

any1 of you can give me a hint ?
i dont understand at all anything of mysql then setup or changing values 
with phpmyadmin.
maybe the "user_query" is totaly wrong ?

thanks

marko