EV 10 and Migration

[AndresMunoz]

I've been tasked with designing an EV10 environment for a new customer of ours. a quick rundown on client environment

• Exchange 2003 (2), migrating to Exchange 2010 in a new forest (Green fields implementation. User accounts will not be migrated)
• Number of user mailboxes: 900
• Number of shared mailboxes: about 600
• Average user Mailbox size: 2.8GB (!)
• Average shared Mailbox size: 1.5GB
• about 400GB in PST files

As mentioned above, client is moving into a green fields environment, and user accounts are not being migrated, however, email is

Migration of all that email will take a lot of time, so my preffered approach would be to archive the source mailbox servers (exchange 2003), then moving the remaining mailbox contents, speeding up the mailbox move. this however, raises the following question.

If the associated mailbox is not the same (as the user object is not the same), how can I associate the archive to the new user mailbox? and I don't want to do this manually.

While my preference would be as above, no decision has been made yet and I'm open to suggestions. the alternative would be to move the mailbox and then archive on the destination exchange servers (2010).

What are your thoughts?

[JesusWept3 · Accepted solution]

can they not preserve the legacyMbxDn? its not really used by anything in exchange or AD anymore, but its ultimately very useful for EV purposes

i mean honestly if you can't keep the mbxdn or the mbxguid the same, you will have to do it manually, not many other choices

[AndresMunoz]

We'll be using FIM (Forefront Identity Manager) to provision the users, so I believe we should be able to keep the legacyMbxDn.

[AndresMunoz]

We have changed our approach. email will be migrated to interim exchange servers, mail will be archived and then mailboxes will be moved to their final destination.