migrating from exchange 2003 to exchange 2013

Since Exchange 2003 and 2013 can't exist in the same domain, you may have to take some in between steps.

Depending on the number of mailboxes, you might be able to dump everything out to PST and then import into 2013. There are tools that can do that as well such as: https://www.codetwo.com/blog/migrating-exchange-2003-straight-to-exchange-2013/

Do you already have a 2013 license, or will you be buying one now? Since FYI 2016 is what you be buying now and then downgrading the license.

Best possible is to move to office 365. if you want to stick on-premises, hire an IT Architect for Exchange, that can help you to perform the migration. Or Microsoft also can help you out. If you want to do it yourself and you have migration experience, you can start with Exchange deployment tool and understand the migration requirement.

In your case, best option to migrate to Exchange 2010 first and then directly to 2016. Skip 2013 altogether. Exchange 2016 is much more simplified and improved compared to 2013. Remember 2019 also coming soon.

Like mine colleges before me said It is NOT POSSIBLE migrate 2003 to 2013 in same forest, because Exchange 2003 and 2013 can't co-exist in one forest.
So if you have a lot of mailboxes and don't want to export all of them to PST file, install new Exchange and import PST to mailboxes you have 2 choices:

1. Backup Exchange using some software with granular recovery option like Symantec Backup Exec, demote your old Exchange, remove from domain, clean Forest from all informations about Exchange, Install new 2012 server with Exchange 2013, create all mailboxes manually and recover all emails from backup to new Exchange.

2. Create new Forest with new DC, join all users to new domain, Install new Exchange 2013 and then transfer all mailboxes using Cross-Forest-Migration

If you have no choice, you can deploy Exchnage 2010 on Windows server 2008, Migrate mailboxes, from 2003, then remove 2003 from domain and Mgrate again to 2013 but this will be very time consuming job.

The best and most convenient approach to you and to your users is to add Exchange 2010 into the environment, (would mean some AD domain and forest upgrade) migrate the users' mailboxes over and remove Exchange 2003. Once there, migrate over to 2016.
You will also need to upgrade your users' Outlook to the version that would allow to connect to the Exchange server which is in use at the time.
You would require a proper SSL certificate, name planning and much much more ...

You can't do migrations directly from Exchange Server 2003 to 2013 because coexistence is not supported by Microsoft. But you can do so by using Kernel Migrator for Exchange software. It can perform Exchange direct migrations in both cross or intra-forest type. Visit https://www.nucleustechnologies.com/exchange-migration/ to know more about its features and support.

Hi,

@Brian B. thank you for mentioning our software.

CodeTwo Exchange Migration tool is a fully featured application that allows you to directly migrate the mailboxes' content from the old environment (Exchange 2003) to the new one (Exchange 2013/2016). No double-hop migration required. We have also an alternative version that handles migration to the Office 365.

There is no downtime for both of the environments so you can perform the process during normal working hours. The mailboxes can be automatically created with preserving chosen old AD attributes. What is more, all old EX addresses are converted (optionally) to SMTP equivalents, so if you are staying with same domain, you will be able to reply on migrated emails out of the box.

The process is handled by MAPI protocol (as the only alternative for old Exchange) and by EWS regarding the target environment. You can create multiple migration jobs so the program allows you to handle the migration topic as you want.

And of course the software comes with free support during your trial. You can test the software for free.

http://codetwo.com/exchange-migration/ 

Cheers,

Thanks to all

My suggestion was exactly same as Ajit so I'm surprised why you did not split points between us. That's why assisted solution is for.

@Tom

i posted the objections. lets wait for the moderator.

the reason why i accepted that solution is because it is well explained.