Hi,

Company B bought a company A and want to migrate company A email domain (companyA.com) to company B(companyB.com) with minimal downtime after domain name is transfered. I am not sure what is the way in order to achieve it without exchange trust or domain trust involved. Once mailboxes are moved or migrated and companyA.com emails start flowing at company B, company A exchange will be decomissioned. The following is the fact.

1. company A exchange runs on exchange 2003. (exchangeA)

2. company B exchange runs on exchange 2003 and exchange 2010.

3. currently site to site vpn is setup

What should I do next? My plan is as below.

1. install new exchange at company A office with companyB domain. (exchangeB)

2. create companyA users accounts on ExchangeB

3. create comanyA users contacts on companyB domain

4. setup companyA recipient policy on exchangeB

5. turn on emails forward to contacts list so that company B can start emailing using distribution list

6. create smtp connector on exchangeB and exchangeA

7. on cut off date, can I just run migrate wizard to move mailboxes? When should I add companyA domain to companyB domain registrar? I am worried about emails loss during transaction time. Turn off email forwarding and when I add companyA domain to companyB, will the emails start going to ExchangeB mailbox? Then later maybe I export pst from exchangeA t import into exchageB? Is there any better way or tools to do it as there are 188 mailboxes on exchangeA.

I am kind of stuck at this stage on planning as I have never performed such project before.

Any suggestions would be greatly appreciated.

Many thanks,

Pwint

I suggest you reading through, http://blogs.technet.com/b/meamcs/archive/2011/06/10/exchange-2010-cross-forest-migration-step-by-step-guide-part-i.aspx and all 3 parts of these blog posts. Also, I remember some really good stuff that can be handy to you during migration is also available at http://www.msexchange.org/articles-tutorials/exchange-server-2010/migration-deployment/deep-dive-into-rich-coexistence-between-exchange-forests-part1.html

Thank you very much. The articles are very interesting and good find. I have been told that the target exchange will be 2003 due to licensing. :-(

I will read through the articles now and see what are my options.

Thanks again for the post.

Cheers,

Glad to help. Do post back in case you have any questions or doubts.

The best and easy way to use third party software, because it will take less time and required no technical skill. Manually most of the chances error occured. Go to Google search for Exchange Migration tool, you will get lots of option. From there one such uitlity is here which is  offering free trial version.

http://www.edbtopst-converter.com/

Thanks