I use FIM to synchronize GALs between two excange orgs. FIM creates a contact object in the foreign exchange org. I want to migrate users from the Windows 2003/Exchange 2003 org to the foreign Windows 2008R2/Exchange 2010 exchange org. The problem is when I delete the Contact object and create a new user object in the Windows 2008R2 / Exchange 2010 org, the LegacyExchangeDN adds a random number on the end, indicating that the LegacyExchangeDN is already in use. This behaviour does not happen in the Windows 2003/Exchange 2003 org. It appears to me that Exchange 2010 is looking tombstoned objects in AD when it checks for LegacyExchangeDN while Exchange2003 does not. Is this a bug or by design??? Does anyone have a solution to the problem?

Hi, Sorry for the delay response. Actually, I could reproduce this issue on my lab. Until now, I am still not sure whether or not that is the product issue. I already sent the issue to our discussion group, and will update you as soon as possible. Thanks AllenAllen Song

Yes this behavior is exhibited when you do something simple like delete a contact and then recreate with the same CN. In previous versions the same LegacyExchangeDN was generated but with 2010 the uniqueness checker queries tombstoned objects. To ensure uniqueness it appends a random number. I guess if you were to undelete an object you may get issues if they are not unique but this is an unlikely scenario.