[Dovecot] Howto create maildir in lower case while user login via imap/pop3?

[Zhang Huangbin]

Hi, all.

I searched mail archives, but no result.

I use OutLook Express on Windows XP as MUA, login username is in upper case,
such as 'AAA at BBB.COM', when login via imap, dovecot create directories:

/home/vmail/
        |- BBB.COM/         # <- Domain name
            |- AAA/         # <- User name
                |- cur/
                |- xxx

Here, domain name and user name are in upper case.

How can i make it create directories in lower case?

#
# dovecot -n
#
# /etc/dovecot.conf
log_path: /var/log/dovecot
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
mail_location: maildir:/%h/%d/%n/:INDEX=/%h/%d/%n/
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/lib/dovecot/imap
mail_plugin_dir(imap): /usr/lib/dovecot/imap
mail_plugin_dir(pop3): /usr/lib/dovecot/pop3
auth default:
  mechanisms: plain login
  user: vmail
  passdb:
    driver: ldap
    args: /etc/dovecot-ldap.conf
  userdb:
    driver: ldap
    args: /etc/dovecot-ldap.conf
  socket:
    type: listen
    client:
      path: /var/spool/postfix/private/auth
      mode: 432
      user: postfix
      group: postfix
    master:
      path: /var/run/dovecot/auth-master
      mode: 432
      user: vmail
      group: vmail

#
# File: /etc/dovecot-ldap.conf
#
hosts           = 127.0.0.1:389
ldap_version    = 3

auth_bind       = yes
dn              = cn=vmail,dc=openbsdonly,dc=org
dnpass          = passwd

base            = o=%d,o=domains,dc=openbsdonly,dc=org
scope           = subtree

deref           = never

user_filter     = (&(mail=%u)(objectClass=qmailUser)(accountStatus=active))
user_attrs      = 
homeDirectory=home,mailMessageStore=maildir:mail,mailQuota=quota=maildir:storage

pass_filter     = (mail=%u)
pass_attrs      = userPassword=password

user_global_uid = 2000
user_global_gid = 2000

default_pass_scheme = CRYPT

-- 
Best Regards.

Zhang Huangbin

- OpenBSD 4.2 -release, i386.
- RHEL 5.1 Client