Есть Dovecot-2.0.4 (компилил так: ./configure --prefix=/usr --with-mysql --sysconfdir=/etc/dovecot --localstatedir=/var --with-ldap)
Вот конфиг dovecot-ldap.conf.ext:
uris = ldap://192.168.0.2:3268
dn = robot@domain
dnpass = secret
auth_bind = yes
ldap_version = 3
base = CN=Users,DC=domain,DC=local
pass_attrs = =uid=5000,=gid=5000,mail=mail=maildir:/home/vmail/%d/%$/Mail,postOfficeBox=quota_rule=maildir:bytes=%$
pass_filter = (&(sAMAccountName=%Ln))
user_attrs = =uid=5000,=gid=5000,mail=mail=maildir:/home/vmail/%d/%$/Mail,postOfficeBox=quota_rule=maildir:bytes=%$
user_filter = (&(|(mail=%Ln@domain.ru)(sAMAccountName=%Ln))(!(userAccountControl:1.2.840.113556.1.4.803:=514)))
Вот лог mail.log:
dovecot: auth: Debug: ldap(user@domain.ru,127.0.1.1): user search: base=CN=Users,DC=domain,DC=local scope=subtree filter=(&(|(mail=user@domain.ru)(sAMAccountName=user))(!(userAccountControl:1.2.840.113556.1.4.803:=514))) fields=mail,postOfficeBox
dovecot: imap(user@domain.ru): Disconnected: Logged out bytes=46/957
dovecot: auth: Debug: ldap(user@domain.ru,127.0.1.1): result: mail(mail=maildir:/home/vmail/%d/%$/Mail)=maildir:/home/vmail/domain.ru/user@domain.ru/Mail
dovecot: auth: Debug: master out: USER#0111#011user@domain.ru#011mail=maildir:/home/vmail/domain.ru/user@domain.ru/Mail#011uid=5000#011gid=5000