I have followed the following steps to create a GAL which 1 condition:
---start---
Create a new gal named Test.
R click and select properties.
Under General, click Modify.
Uncheck all except "users with exchange mailboxes."
Click the advanced tab.
Drop down field and click User-> Email Address, then select "ends with" and type in your test domainand click Add.
Hit Find Now to make sure you get the expected results.
That should give you a list of the users with that domain as an email address.
----end----
In regards to adding more conditions to the GAL filter.
It seems that if I add another similar condition that ends with a different domain name, it seems to be filtering CONDITION 1 AND CONDITION 2 which will not show any results when I test it with Find Now, how can I specify CONDITION 1 OR CONDITION 2 so that all email address that ends with either A.com OR B.com will turn up in the filter.
Thanks in advance.
I don't have an Exchange 2003 still to test on, but if you still need to create one of these in Exchange 2003 you can create the LDAP query as you listed in your original post but use the "|" instead of "&" when it creates the custom LDAP query. This would query OR instead of AND.
(for the comments, Exchange 2003 had this ability in the GUI, pre-powershell days).