Hi Experts, I need some thought from you. Scenario: A centralized server, which is installed Sendmail LDAP directory service with DirSync program, is used to read and write back to (Or Synchronize) 94 Exchange 5.5 directories. The goal is to let every Exchange 5.5 organization to have a unified GAL which contains all 94 user accounts and recipients. Plan: We plan to use Sendmail program called DirSync which can do LDAP update to read directly from 94 Exchange 5.5 Directories write data into the centralized LDAP server and inject the changes that need to be synchronized back to Exchange. These changes are updates that came via DirSync from the other 93 Exchange 5.5 directories. I believe - but I am not 100% certain - that when we update or synchronize other 93 Exchange 5.5 directories into a Exchange directory which contains 94 directory data, the GAL in the Exchange is updated automatically. In other words, I think that the GAL is just a particular view of the Exchange directory. I want to make sure the following concept I have is correct. Concept is: Dirsync will update the Exchange 5.5 directories via LDAP. If the GAL has direct visibility into the Exchange 5.5 directory, then the GAL will reflect the updates and therefore will contain the addresses across all 94 directories. We don't have to use MIIS do the GAL sync. We can use the DirSync program to do the same. Thanks for any feedback, -LiMing