Company Split - how to move Exchange 2003 mailboxes to new domain

Hello Experts,
Company A has been planning a split from Company B.  In preparation, Company A bought their own domain name which was added to Exchange to receive mail (in Default Recipient Policies).  
Now Company A is making permanent split.  A new AD Domain will be built and a new Exchange server if necessary (which I believe it is).  Million dollar question is how would you get the email off the old domain to the new domain?
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.


Best and clearest method would be to EXMERGE the mailboxes out and into the new server. Just ensure that all mailboxes are below 2GB or your import will fail on those respective mailboxes.

Hope this helps.
kialnAuthor Commented:
So they will import to the same username even though it will be a completely different domain?  (tho the email domain name will be the same).
AmitIT ArchitectCommented:
Another way:

Change the mail delivery path to a PST. This way all data will be download to the PST files in local Outlook. Outlook support 20GB PST as it uses UNICODE format, but Exmerge uses ANSI format so above 2GB PST corrupts.

Then change the Outlook profile to new server and merge PST data back to new Exchange.


Use tools like Quest for migration

First is free solution, second is paid solution

Hope this helps
Yes that's right, as long as the username matches and the user has rights to the mailboxes, everything should migrate across. You haven't mentioned how many user mailboxes are in question, however this will be the best and automated method.

For mailboxes over 2GB, use Outlook to perform a mailbox export to get around the size limitation.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
kialnAuthor Commented:
There are only 35 users, so sounds like exmerge would be the way to go.  Thanks so much!
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.