Hi,

I'm performing a cross forest migration in an environment where domain migration has already been done and users are accessing their mailboxes from old domain through linked mailboxes. The users have been migrated to new domain with ADMT and the exchange attributes have been excluded.

Old domain has one 2010 exchange server (Version 14.3, Build 123.4) and new environment consists two 2013 exchange servers (Version 15.0, Build 1044.25) which are configured as a DAG.

Now I'm trying to figure out what would be the best way to get mailboxes migrated to new users in new domain with minimal effort and downtime. PrepareMoveRequest script seems not to be the solution since the user objects have already been migrated to new domain and they cannot be overwritten since they are in use already for other AD usage.

Any tips how this should be done are very appreciated since the web is full of cross migration guides, but none I can find matches our scenario where users have already been migrated and linked mailboxes used.

I will tell more information about the environment if thats necessary.

Thanks in advance!

• Edited by Timo Heinonen 20 hours 36 minutes ago

For cross forest migration visit http://blogs.technet.com/b/meamcs/archive/2011/06/10/exchange-2010-cross-forest-migration-step-by-step-guide-part-i.aspx where you got solution.

If Exchange Server is corrupted then using Kernel for Exchange Server Recovery Software you can repair and migrate it to Outlook pst, Live Exchange Server and Office 365. Go to http://www.nucleustechnologies.com/Exchange-Server-Data-Recovery.html to know more about the Exchange Recovery Tool.

• Marked as answer by Timo Heinonen 48 minutes ago

The link you provided gave me one hint I've missed. Now I'm able to migrate a mailbox cross forests and can continue the project to create a co-existance.

It's funny how you can search and search for an answer without results but when you ask from the public, someone always has the answer for you :)

Thank you Peter!