Hello,

I am planning the upgrade from a 2003 domain to 2012, but I have an old exchange 2003 server not being used, as I have fully migrated to office365 - with cutover migration (No hybrid deployment).

1. Can I simply turn off the exchange server?

2. If I decommission the exchange server, I assume that all exchange attributes are removed, if so, does this create an issue with upgrading domain to 2012 after?  or using DirSync with password sync for office365 later?

Thank you for any input.

• Moved by Mahdi Tehrani Saturday, April 18, 2015 6:15 AM

Hi

Since you have done a cut over migration there shouldn't be any issue in decommissioning

The best approach would be 

1) Just check and ensure that there are no applications in your on prem relaying on Exchanre 2003

2) Turn off the Exchange server for a day and see if you are getting any complaints. Monitor it for a week

3) If everything is fine you can uninstall the server. Uninstalling Exchange 2003 will no impact you in your server upgrade from 2003 to 2012 and also will not make any impact for dirsync upgrade

Hi Thank you,

With my first question (1), I intended to ask if it was ok to simply turn off exchange, and not even uninstall it.

1. Would this be a acceptable approach?  I am thinking it would not be good, since all the attributes would still live in the directory, but since I am not upgrading exchange any longer, it may cause issues in the future?

2. Am I correct in believing that once I uninstall the exchange organization (I only have the 1 exchange server), all attributes in AD will be removed that are related to exchange?

3. Assuming my #2 question is correct, with DirSync, since there is no exchange attributes in my on-premises AD, would this not cause either sync problems, or possible remove exchange attributes in Exchange Online/Office365 (I can't imagen somehting like that would happened, but wanted to ask)?

Thank you

1. No do not just "turn off" the legacy Exchange Server.  While this is not causing any issues with your current setup, it can lead to issues later on down the road.  Anything that integrates with Active Directory needs to be properly decommissioned.
2. It shouldn't remove anything that;s needed regarding Office 365

Thank you

1. Would this be a acceptable approach?  I am thinking it would not be good, since all the attributes would still live in the directory, but since I am not upgrading exchange any longer, it may cause issues in the future?

As Hinte say, don't just turn it off, it will take some time to uninstall it properly, however you'll have a clean AD. If you don't, when you'll need it you will have to resort on a exchange recovery or ADSIEdit, which can be challenging.

If you ever need to go Hybrid for some reason or want a rollback in the future, that will be just like installing a fresh Exchange.

On a real case scenario for one customer that want a  O365 rollback, I have to clean Active Directory using powershell scripts and ADSIEdit, which costed much more than just uninstalling Exchange 2003.

Ok, sounds like installing an exchange server in the future should not be a big deal?  So I can then remove exchange 2003 organization.

Or would you say that keeping an exchange server in the organization is a better approach, however, as I understand I will need to upgrade to exchange 2010 then to exchange 2013, yes?

Thanks.