Company A runs exchange 2010, company B runs exchange 2003.
Company A buys company B. Company A wants to move company B users to Company A exchange organization. Company A has manually created the user mailboxes on 2010.
What is the best way to migrate users from company B to company A while keeping their mailbox data emails etc in tact?
Ideally this will not involve paid third party tools but if that is the best way please recommend
Thanks