Please Help me,

i have question about migration plan exchange with different domain and version.

currently i have domain abc.com with exchange server 2003, now im going to migrate them to exchange 2013 in def.com.

if they are in the same forest, what possibility method to do that ?

thanks for advice.

Hi arimuhammads,
You cannot upgrade 2003 to 2013 either you upgrade to Exchange2007SP3  or Exchange2010 then upgrade to Exchange2013. http://blogs.technet.com/b/mconeill/archive/2013/04/03/migration-from-exchange-2003-to-2013-a-no-go.aspx or you export mailboxes to PST and import into Exchange2013.

FYI Exchange supports only one Exchange organization per forest.
I suggest you install Exchange2013 in the root domain

i think, exchange supports more organizations using add more accepted domain. cmiiw

Are these domain (abc.com and def.com domain) accepted domains  or AD domains within the forest?
If they are the accepted domains you can add more accepted domains within same exchange organization for hosting multiple SMTP addresses.
If it is a SMTP domain name change please check this
https://social.technet.microsoft.com/Forums/exchange/en-US/184928f8-8185-4270-9cee-b8c2e05549a0/exchange-2010-add-new-email-address-space-and-additional-smtp-address-to-all-recipients?forum=exchangesvrdeploylegacy

ok, for you info, it is configured with different forest (acquitition company). so it's possible performed by using import pst, isn't it ?

what if i have 500 users ? should i export them to pst one by one ? or is there any complicated way to make it more simple ?

please let me know.

thanks.

If you are planning to do a inter-forest migration please check my comments in this thread
https://social.technet.microsoft.com/Forums/exchange/en-US/7ee1cc31-643a-4eb5-a685-45153a3d6786/interdomain-migration-of-mailboxes-and-users?forum=exchangesvrdeploylegacy