We have a requirement to manually migrate approx 10 pilot users from one domain to another. Say I have a user named User1 and i wanna migrate mailbox for user1 from abc.com to xyz.com  , what would be best approach to migrate . Pleas

Hi Aditya,

Can you know the exact requirement

Is there only 10 users in the forest abc.com 

What is the pilot users ? Are there more users apart from these 10 

If its only 10 users the simplest solution would be just export mailboxes from abc  create new mailboxes for them and import it on the new mailbox

If you are have more number of users then cross forest migration is the best solution

Probably you would need to share a name space if these 2 forests are very large and if the migration takes time

refer this post for understanding cross forest migration 

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

we took over a small firm , target is about max 50 to 60 users as of now we are testing out with 10 users, so just exporting & importing back PST from source to target would do. Apart I am confused about how to proceed with any attached shared mailbox, active-sync  for these pilot users and considerations about their existing group membership . Please

Hi,

As Sathish mentioned, export-mailbox and import-mailbox only handle the data with .pst file, and this command cant be used for public folder.
More details about Mailbox Import and Export Requests, for your reference:
https://technet.microsoft.com/en-us/library/ee633455%28v=exchg.141%29.aspx?f=255&MSPPError=-2147217396

If you want to remain the relationship of user and group, please run cross forest migration:
1. Create forest trust.
2. Prepare required attribute for cross forest mailbox moving, then run ADMT to sync attribute.
3. Run New-MoveRequest to complete moving.
More details please refer to the link as Sathish mentioned.

Thanks