As a result of a merger, I have two Exchange 2003 servers, each in a different Active Directory forest/domain. I would like to move the mailboxes from Exchange1.domainA.local to Exchange2.domainB.local.
There is network connectivity between the two domains/forests and I have established a two-way external AD trust. DNS is fine, hence the trust.
Various Technet pages seem to indicate that the mailbox move is possible using the Exchange 2003 Migration Wizard, however so far I have been unsuccessful.
I guess the crux of the problem is that I cannot see the target Exchange server (Exchange2.domainB.local) when I run the Migration Wizard on Exchange1.domainA.local. The drop down box only shows the local Exchange server as a possible target.
This Technet article (http://technet.microsoft.com/en-us/library/aa996952%28EXCHG.65%29.aspx) seems to suggest that the user running the Migration Wizard needs to be a Full Exchange admin on the target Exchange server. You can't make a user from another forest an Exchange admin directly, but I have managed to achieve this by adding domainA\administrator to the BUILTIN\administrators group on domainB, and then adding BUILTIN\administrators as a Full Exchange admin in System Manager. Hasn't helped though.
I am aware of the Active Directory Migration Tool, and can move AD accounts across fine.
I fixed this by adding an entry in the hosts file on servera pointing to serverb. I think this is some sort of netbios thing - servera needs to be able to resolve serverb without performing a DNS query.