Hello, I'm looking into using the Availability service in Exchange 2007 (and eventually 2010) to replace the functionality of the InterOrg Replication tool. There is one requirement that I want to understand better and I'm hoping someone here can help. The article I read (http://technet.microsoft.com/en-us/library/bb125182%28EXCHG.80%29.aspx) states the following: "To configure Microsoft Windows for a cross-forest topology, you must install and configure GAL Synchronization (GALSync). " Can anyone tell me if this is a hard requirement or not? I mean, is there something special that the GALSync tool is going to do to the mail-enabled contact (besides keep them synchronized) that a manually created contact wouldn't do? I ask because I have another solution for creating contacts in each Exchange organization and it works quite well and is built into our enterprise role system, so I don't want to switch. Thanks in advance!

Hi, Of course, created the contact manually is feasible. Use the GALSync tool is for lots of users which reduce the labor. Thanks AllenAllen Song