[imp] Horde integration problem with Postfix

[sugo]

Hello,

I am migrating from Horde+qmail to Horde+postfix.
All the email accounts are stored in a Mysql database.
To make qmail works, the mailbox field of each user is, for example:

/var/spool/pop/domain/site.com/username

For Postfix, instead, I need to change to:

/var/spool/pop/domain/site.com/username/Maildir/

the problem is that the authentication with Horde doesn't work anymore
when I update the tables in this way, instead the authentication by POP3
or IMAP (for example setting up the account on any email client still
works).

Have you got any help?

Below the configuration files:

../horde/config/conf.php:

<?php
/* CONFIG START. DO NOT CHANGE ANYTHING IN OR AFTER THIS LINE. */
// $Horde: horde/config/conf.xml,v 1.74.2.48 2007/02/02 11:03:05 jan Exp $
$conf['debug_level'] = E_ALL & ~E_NOTICE;
$conf['max_exec_time'] = 0;
$conf['compress_pages'] = true;
$conf['umask'] = 077;
$conf['use_ssl'] = 2;
$conf['server']['name'] = $_SERVER['SERVER_NAME'];
$conf['server']['port'] = $_SERVER['SERVER_PORT'];
$conf['session']['name'] = 'Horde';
$conf['session']['use_only_cookies'] = true;
$conf['session']['cache_limiter'] = 'nocache';
$conf['session']['timeout'] = 0;
$conf['cookie']['domain'] = 'domain.net';
$conf['cookie']['path'] = '/horde';
$conf['sql']['persistent'] = false;
$conf['sql']['username'] = 'horde';
$conf['sql']['password'] = 'password';
$conf['sql']['hostspec'] = 'robin.domain.it';
$conf['sql']['port'] = 3306;
$conf['sql']['protocol'] = 'tcp';
$conf['sql']['database'] = 'horde';
$conf['sql']['charset'] = 'iso-8859-1';
$conf['sql']['phptype'] = 'mysql';
$conf['auth']['admins'] = array('username at domain.net');
$conf['auth']['checkip'] = true;
$conf['auth']['checkbrowser'] = true;
$conf['auth']['alternate_login'] = false;
$conf['auth']['redirect_on_logout'] = 'http://www.domain.net/';
$conf['auth']['params']['app'] = 'imp';
$conf['auth']['driver'] = 'application';
$conf['signup']['allow'] = false;
$conf['log']['priority'] = PEAR_LOG_NOTICE;
$conf['log']['ident'] = 'HORDE';
$conf['log']['params'] = array();
$conf['log']['name'] = '/tmp/horde.log';
$conf['log']['params']['append'] = true;
$conf['log']['type'] = 'file';
$conf['log']['enabled'] = true;
$conf['log_accesskeys'] = false;
$conf['prefs']['params']['driverconfig'] = 'horde';
$conf['prefs']['driver'] = 'sql';
$conf['datatree']['params']['driverconfig'] = 'horde';
$conf['datatree']['driver'] = 'sql';
$conf['group']['driver'] = 'datatree';
$conf['cache']['default_lifetime'] = 1800;
$conf['cache']['params']['dir'] = Horde::getTempDir();
$conf['cache']['params']['gc'] = 86400;
$conf['cache']['driver'] = 'file';
$conf['token']['params']['driverconfig'] = 'horde';
$conf['token']['driver'] = 'sql';
$conf['mailer']['params']['sendmail_path'] = '/usr/local/qmail/bin/sendmail';
$conf['mailer']['params']['sendmail_args'] = '-oi';
$conf['mailer']['type'] = 'sendmail';
$conf['vfs']['params']['vfsroot'] = '/tmp';
$conf['vfs']['type'] = 'file';
$conf['sessionhandler']['type'] = 'none';
$conf['problems']['email'] = 'webmaster at example.com';
$conf['problems']['maildomain'] = 'example.com';
$conf['problems']['tickets'] = false;
$conf['menu']['apps'] = array();
$conf['menu']['always'] = false;
$conf['menu']['links']['help'] = 'all';
$conf['menu']['links']['help_about'] = true;
$conf['menu']['links']['options'] = 'authenticated';
$conf['menu']['links']['problem'] = 'all';
$conf['menu']['links']['login'] = 'all';
$conf['menu']['links']['logout'] = 'authenticated';
$conf['hooks']['permsdenied'] = false;
$conf['hooks']['username'] = false;
$conf['hooks']['preauthenticate'] = false;
$conf['hooks']['postauthenticate'] = false;
$conf['hooks']['authldap'] = false;
$conf['portal']['fixed_blocks'] = array();
$conf['accounts']['driver'] = 'null';
$conf['imsp']['enabled'] = false;
$conf['kolab']['enabled'] = false;
/* CONFIG END. DO NOT CHANGE ANYTHING IN OR BEFORE THIS LINE. */


../horde/imp/config/conf.php


<?php
/* CONFIG START. DO NOT CHANGE ANYTHING IN OR AFTER THIS LINE. */
// $Horde: imp/config/conf.xml,v 1.53.2.18 2007/05/03 15:24:51 chuck Exp $
$conf['utils']['gnupg_keyserver'] = array('pgp.mit.edu');
$conf['utils']['gnupg_timeout'] = '10';
$conf['menu']['apps'] = array('horde');
$conf['user']['select_sentmail_folder'] = false;
$conf['user']['allow_resume_all_in_drafts'] = false;
$conf['user']['allow_folders'] = true;
$conf['user']['allow_resume_all'] = false;
$conf['user']['allow_view_source'] = true;
$conf['user']['alternate_login'] = false;
$conf['user']['redirect_on_logout'] = 'http://www.domain.net/';
$conf['server']['server_list'] = 'shown';
$conf['server']['sort_limit'] = '0';
$conf['server']['cache_folders'] = false;
$conf['server']['cache_msgbody'] = false;
$conf['mailbox']['show_attachments'] = true;
$conf['mailbox']['show_preview'] = true;
$conf['mailbox']['show_xpriority'] = true;
$conf['fetchmail']['show_account_colors'] = true;
$conf['fetchmail']['size_limit'] = '4000000';
$conf['msgsettings']['filtering']['words'] = './config/filter.txt';
$conf['msgsettings']['filtering']['replacement'] = '****';
$conf['spam']['reporting'] = false;
$conf['notspam']['reporting'] = false;
$conf['msg']['prepend_header'] = true;
$conf['msg']['append_trailer'] = true;
$conf['compose']['allow_cc'] = true;
$conf['compose']['allow_bcc'] = true;
$conf['compose']['allow_receipts'] = true;
$conf['compose']['special_characters'] = true;
$conf['compose']['use_vfs'] = false;
$conf['compose']['link_all_attachments'] = false;
$conf['compose']['link_attachments_notify'] = true;
$conf['compose']['link_attachments'] = true;
$conf['compose']['add_maildomain_to_unexpandable'] = false;
$conf['compose']['attach_size_limit'] = '0';
$conf['compose']['attach_count_limit'] = '0';
$conf['hooks']['vinfo'] = false;
$conf['hooks']['signature'] = false;
$conf['hooks']['trailer'] = false;
$conf['hooks']['fetchmail_filter'] = false;
$conf['hooks']['mbox_redirect'] = false;
$conf['hooks']['mbox_icon'] = false;
$conf['hooks']['spam_bounce'] = false;
$conf['maillog']['use_maillog'] = true;
$conf['tasklist']['use_tasklist'] = true;
$conf['notepad']['use_notepad'] = true;
/* CONFIG END. DO NOT CHANGE ANYTHING IN OR BEFORE THIS LINE. */

Thanks!