Keep in mind that this will add another task to the process of managing recipients.When users are created or moved to or from the OU, you have to make sure that the particular attribute you decide to use is populated or removed.
The only problem I have now is how to ger the LDAP query working properly.
As I mentioned I created new OU's in the AD and I inserted my 3 sites there, under that I inserted the users for each site, and I want the recipient policy to be applied according to OU.
Exchange Server 2003 communicates with directory servers to update recipient objects (such as mailbox-enabled user accounts and mail-enabled groups) with e-mail addresses, according to the recipient policies defined for the organization.
To do this, Exchange Server 2003 uses Recipient Update Service, a component of System Attendant.
These rules should not be deleted, and the recipient policy GUI actually prevents you from doing so.
However, if any of these are deleted using a tool like ADSIEdit, which the Exchange System Manager GUI has no control over, it will prevent critical services like the information store service and MTA Stacks service from starting. Recipient policies based on organizational units (OU): Another misconception and a frequently asked question in many forums is how one can apply a recipient policy to recipients in a particular OU, or apply the policy to an OU so it gets applied to all recipients in that OU. Recipient policies are applied to recipients filtered on recipient attributes, such as department, location, city, or country.
The method that Recipient Update Service uses to perform a search is determined by the actions that an Exchange administrator takes in Exchange System Manager.
For example, in Exchange System Manager, you can right-click a Recipient Update Service configuration object and select the Rebuild command to recalculate address list memberships and the recipient policy settings of all recipients in a domain at the next scheduled interval.
Have 3 companies working from one server, with 3 different mail addresses.
I tried setting up 3 recipient policies, and I think I have done that ok.
If the recipient policy is being used to assign an SMTP address from a different address space, you can generate different UPN suffixes for those domains.