XADM: How to Create a Custom Recipient Policy Based on Routing Groups (259381)

SUMMARY

In Microsoft Exchange Server 5.5, it is possible for each site in an organization to have an SMTP domain associated with it. This way, every user mailbox can automatically have its SMTP address generated by Exchange Server 5.5 Site Addressing when it is created, in the form:

alias@site.domain.com

Some Microsoft Exchange 2000 Server administrators may want to have a recipient policy based on Routing Groups because this best mimics the Exchange Server 5.5 environment. However in Exchange 2000, there is no equivalent to Site Addressing on a Routing Group level. This type of recipient policy is not a default feature of Exchange 2000 and requires customization.

MORE INFORMATION

Exchange 2000 cannot use recipient policies based on Routing Groups because there is no attribute in Active Directory that ties a user to a Routing Group. Therefore, Exchange 2000 recipient policies, which are based on LDAP search filters (in accordance with Request for Comments [RFC] 2254) will not work.

However, users belong to servers and servers belong to Routing Groups, so implicitly, you can create a recipient policy based on servers. Although this involves a little more customization and administration, it achieves the effect you want.

NOTE: The Field Picker in the recipient policy user interface (UI) only uses ANDs in the LDAP search filter; therefore, do not use it because it creates a policy for each server. To cut down on the number of recipient policies, use a custom search string with ORs on the server name.

With customization, you will have a recipient policy for each Routing Group, with a custom query string that resembles the following:

(&(mail=*))(|(homeMDB=cn=Server1, etc, etc)(homeMDB=cn=Server2, etc,etc)(homeMDB=cn=Server3, etc, etc))

The pipe (|) in the expression gives you a logical OR.

To create and apply a recipient policy based on this custom query string:

In Exchange System Manager, right-click the Recipient Policies container, click New, and then click Recipient Policy.
Give the policy a name, and then click Modify.
In the Find list, click Custom Search. Then click the Advanced tab, and type the LDAP query in the space provided.

The caveat here is that you need to put some manual process in place to change the recipient policies as servers are moved to, added to, and removed from Routing Groups.

For more information on the string representation of LDAP search filters, see the full text of RFC 2254.