Tuesday, October 27, 2015

New Office 365 Outlook is not compatible with Exchange Server 2003/2007.

We have customers who works with Exchange 2003/2007 and Windows 2003 still. Those customers obviously want Office 365 with Exchange Online instead of 2-hop migration to latest Exchange Server.
With the release of Office 365 2016 it is no longer possible to connect Office 365 Outlook 2016 to Exchange Server 2007 (and obviously to Exchange Server 2003). Why do I need Office 365 Outlook connected to legacy Exchange Server?
It is best practice first to update client versions prior to Exchange Online mailbox migration in order to prepare clients for the new Exchange environment. But you stuck here because new Outlook 2016 won't connect to Exchange Server 2003/2007 and obviously you would upgrade your Office installation right after mailbox switchover to Exchange Online to reduce downtime with your current mail system.
If you did Office 365 package installation prior mailbox synchronization to Exchange Online you will get following message for your on-premise based Outlook profiles (assuming the account was not removed from the profile on first run):
The resource that you are trying to use is located on an unsupported version of Microsoft Exchange.
Luckily you have workaround for Exchange Server 2007 based deployments.

Deploy Outlook Office 365 2013
Outlook Office 365 2013 still supports Exchange Server 2007 connectivity. Just prevent Office 365 2013 automatic upgrade to Office 365 2016 during Exchange Server 2007 to Exchange Online migration. 
If you will try to download Click-To-Run package directly from Office 365 portal you will get Office 365 2016 now. Discovered alternative way is Office Deployment Tool (ODT) usage. There are two different versions of the ODT available – one for Office 2013 and a different one for Office 2016. Each ODT works only with that specific version of Office. You can download Office 2013 Deployment Tool from the Microsoft Download Center by using the following link: Office Deployment Tool (Office 2013 version).Then:
setup.exe /download Myconfigfile.xml
where:

  • Myconfig.xml is the location of the custom Configuration.xml file, Myconfig.xml in this example
  • setup.exe is the Click-to-Run Office Deployment Tool (ODT) executable
  • /download runs the tool in download mode

The following procedure requires a custom Myconfigfile.xml file that must provide the following information:
  • Product(s)
  • OfficeClientEdition (attribute of Add element). Specifies the edition of Click-to-Run for Office 2013 product to use: 32- or 64-bit.
  • Language(s)
Myconfigfile.xml example:

<Configuration>
   <Add SourcePath="\\server\Office15" OfficeClientEdition="32">
    <Product ID="O365ProPlusRetail" >
     <Language ID="en-us" />      
    </Product>
   </Add>
<Updates Enabled=”TRUE” AutoUpgrade=”FALSE”/>
</Configuration>
This Myconfigfile.xml configuration file specifies that Office 365 ProPlus 32-bit edition be downloaded in English to the \\server\Office15 shared folder and prevent automatic upgrade from Office 365 ProPlus 2013Product IDs that are supported by the Office Deployment Tool for Office 365 Click-to-Run can be found in KB2842297
Check my earlier blog post how you can control automatic Office 365 upgrade (disable/enable upgrade) at enterprise level.