We will create a basic LDAP configuration for Dovecot 2.4 which features new confguration syntax. The example uses asynchronous lookups for userdb and passdb queries.

## LDAP

ldap_uris = ldap://ldap.example.com:389
ldap_auth_dn = cn=mail,ou=Services,dc=example,dc=com
ldap_auth_dn_password = <secret_password>
ldap_base = ou=Users,ou=Mail,dc=example,dc=com
ldap_starttls = yes

passdb ldap {
  passdb_use_worker = yes
  passdb_ldap_filter = (&(objectClass=mailUser)(mailDrop=%{user})(!(mailEnabled=FALSE)))
  ldap_bind = yes
  fields {
    user = %{ldap:mailDrop}
  }
}

userdb ldap {
  userdb_use_worker = yes
  userdb_ldap_filter = (&(objectClass=mailUser)(mailDrop=%{user})(!(mailEnabled=FALSE)))
  iterate_filter = (objectClass=mailUser)
  iterate_fields {
    user = %{ldap:mailDrop}
  }
  fields {
    user = %{ldap:mailDrop}
    home = %{ldap:mailHomeDirectory}
    uid = %{ldap:mailUidNumber}
    gid = %{ldap:mailGidNumber}
    quota_storage_size = %{ldap:mailQuota}
    acl_groups = %{ldap:mailGroupACL | default ('')}
    }
}

service auth-worker {
  unix_listener auth-worker {
    user = doveauth
  }
  user = doveauth
}