Here is the deal. We have 2 forests & domains with a 2 way trust between the 2 forests & domains. 1 forest & domain is Windows AD 2000/Exchange 2003 (Setup A)and the other forest & domain is Windows 2008 R2 + Exchange 2010 (Setup B). Each user in Setup A has a corresponding user account in Setup B. We would like to grant each corresponding Setup B account full mailbox permissions to its associated Setup A mailbox, that is User1 in Setup B needs to be granted full mailbox permissions in Setup A environment (User1 mailbox in Setup A). Is there a way to do this in bulk. We have just over a 1000 users. I have looked at ADMODIFY but I do not see a way to make it work for my requirements. Thanks in advance for your help. TD

Hi TD, Your environment : Setup A : Exchange 2003/Windows AD 2000 Setup B: Exchange 2010/Windows 2008 R2 There is a 2 way trust between the 2 forests and domain. You problem: You want each user in Setup A has a corresponding user account in Setup B, grant each corresponding Setup B account full mailbox permissions to its associated Setup A mailbox. Why do you want to do that(grant each corresponding Setup B account full mailbox permissions to its associated Setup A mailbox) ? When you want user1 in setup B to be granted full mailbox permissions in setup A environment (user1 mailbox in setup A), you can just add “full access permission” in ADUC. (because setup A is Exchange 2003, you can give full access permission from ADUC) So far as I know, it is impossible to bulk grant “full mailbox permissions” to multiple users in Windows 2000. Thanks, Evan Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.