LDAP Mail Integration

LDAP can be used to identify mail recipients by configuring the mail transport agent (MTA) to issue queries to a suitable service. Where necessary, the following definitions need to be incorporated into the example configuration files given below:

Definition Purpose
LDAP_SERVICE_BIND_DN LDAP user identity to connect to the service
LDAP_SERVICE_PASSWORD LDAP user password for connection
LDAP_HOST The host providing the LDAP service
LDAP_PORT The port number of the LDAP service
LDAP_BASE_DN The section of the database to search

Using LDAP with Exim

Example configuration files for Exim are distributed in conf/exim/ldap:

File

Purpose

010_exim4-config_ldap_people_outgoing

Defines recipients and outgoing mail routing

020_exim4-config_ldap_people

020_exim4-config_ldap_resources

020_exim4-config_ldap_people_outgoing_recipients

Where local SMTP routing is being performed and the recipients are local system users, the following file is also useful:

File

Purpose

020_exim4-config_ldap_people_local_system

Defines routing for local recipients for delivery to local system mailboxes

These files can be incorporated into the Exim configuration. On Debian systems, they can be copied into /etc/exim4/conf.d/router.

Using LDAP with Postfix

Example configuration files for Postfix are distributed in conf/postfix/ldap:

File

Purpose

main.cf.example

Defines recipients and outgoing mail routing (for inclusion in main.cf)

virtual_alias_maps_people.cf

Defines recipients and outgoing mail routing

virtual_alias_maps_people_outgoing.cf

virtual_alias_maps_resources.cf

The following files are common to LDAP and simple integration and are found in conf/postfix:

File

Purpose

master.cf.items

Mail handler definitions for the imip-agent transports

transport

Transport definitions for /etc/postfix/transport

virtual

Outgoing message routing for /etc/postfix/virtual

These files can be incorporated into the Postfix configuration. On Debian systems, master.cf.items can be merged into /etc/postfix/master.cf, whereas the other files can be merged into any existing files of the same names in /etc/postfix.

LDAP Representations for Mail Recipients

Relevant LDAP resources for structuring recipient information include the following:

RFC

Relevance

RFC 2307

Defines the posixAccount object class

RFC 2739

Defines the calEntry object class supporting calFBURL

RFC 2798

Defines the inetOrgPerson object class

RFC 4524

Defines the mail attribute

An additional draft RFC describes the mailRecipient object class:

Resource schemas for LDAP are not effectively standardised for the purposes of this software. A useful object class, inetResource, was defined for the iPlanet Calendar Server:

Although Kolab maintains notions of resources, they are tied up with the notion of a shared folder and the kolabSharedFolder object class, although the mailRecipient object class is employed by resources in Kolab.