[Dovecot] Prefetch help

[Romer Ventura]

Hello,

    I am trying to use userdb prefetch so that I don't do an extra LDAP
lookup and I am having some problems:

Here is my dovecot-ldap.conf
# cat /etc/dovecot/dovecot-ldap.conf
hosts = 192.168.50.30 192.168.50.31
base = ou=HST-Users,dc=h-st,dc=com
ldap_version = 3
auth_bind = yes
dn = cn=ldap,cn=Users,dc=h-st,dc=com
dnpass = <PASSWORD>
user_attrs = 
sAMAccountName=mail=maildir:/home/vmail/%Ud/%Ln/Maildir/,=gid=1000,=uid=1001
user_filter = (&(objectClass=person)(mail=%u))
#pass_attrs = 
sAMAccountName=mail=maildir:/home/vmail/%Ud/%Ln/Maildir/,=gid=1000,=uid=1001
pass_filter = (&(objectClass=person)(mail=%u))

This works just fine and it only authenticates if the user's email field has
an email address, which is what I want.

But I cant get it to work with prefetch. How could I accomplish that..?

Thanks