Custom address lists can be used to provide a filtered view of the Global Address List (GAL) based on an LDAP query, similar to the way Query Based Distribution Groups work. It leverages the same mechanism used for the built-in address lists provided by Exchange ("All Contacts", "All Users", etc.). Custom address lists are dynamic and are available to all users in the organization. Common custom address lists might be "All Resources", "All Pagers", etc.
Microsoft article How to Create an Address List describes how to create a custom address list in Exchange 2003. The similarly titled, How to Create an Address List describes how to create one in Exchange 2007.
Once you create the new address list, you must configure a filter. The following is an LDAP query example that will filter all contacts with the word "carpenter" in the Notes field in the Telephone tab in AD. It is written as a single line, but is wrapped here for clarity.
(&(&(&(& (mailnickname=*) ( (&(objectCategory=person)(objectClass=contact)) )))(objectCategory=user)(info=*carpenter*)))Note that objectClass could be changed from "contact" to "user" to filter user objects. The word "info" in this query is the AD attribute we're searching for. Any AD attribute can be used. Use ADSIEdit to view attribute names and values.
The search string above is "*carpenter*, which uses wildcards and means "contains the word 'carpenter'". A search for "carpenter" (no wildcards) will match only the word. The string "carpenter*" (trailing *) means "begins with the word". The string "*carpenter" means "ends with the word". The search sting is not case sensitive, but it must be spelled correctly to match the filter.
If you were to create two address lists, one for "All Plumbers" and another for "All Carpenters", and the Notes field for a contact contains "Plumber, Carpenter", the contact will be included in both custom address lists.
As another example, this filter can be used for an address list for resource mailboxes, such as conference rooms. Just be sure to begin the display name for the resource mailboxes with "ZZ-".
(&(&(&(& (mailnickname=*) ( (&(objectCategory=person)(objectClass=user)) )))(objectCategory=user)(displayName=zz-*)))Note: Because custom address lists are dynamically created by Exchange, they are only available to users who are connected to an Exchange server. Users using Cached Exchange Mode who are working offline will not have access to the custom address lists since Outlook can only display one container (the OAB). All contacts will still show up in the OAB.
I've used this process for many clients of all sizes and it works great, with no noticeable affect on AD or Exchange performance.