Updated 10/28/2013: You can now download the fixed version directly without having to contact Microsoft product support and opening a case. You can download the updated connector here: http://www.microsoft.com/en-us/download/details.aspx?id=38791
As many of you discovered and pointed out, there is a bug in the Exchange Connector 3.0 RTM that is related to extending the work item classes data model with custom properties. For example, this could happen when you import the Send Email MP which extends the incident class. When this happens, the impacted work item will not be updated and you will see an event like this in the Operations Manager event log:
Exchange Connector: Unable to process mail item. Subject="xxxxxxxxxxxxx ID: [IR###]", Error Message=The key value of an object cannot be changed.
A fix is available for this issue now by calling Microsoft support and creating a case. We encourage you to only use this approach if it is absolutely necessary. A new build of the Exchange Connector 3.0 with this fix will be available in 1-2 months and will be available for download without creating a support case. That will be much faster/easier if you can wait for that.
Thank you for your patience and helping us identify this issue!
J.C. Hornbeck | Solution Asset PM | Microsoft GBS Management and Security Division
System Center All Up: http://blogs.technet.com/b/systemcenter/
System Center – Configuration Manager Support Team blog: http://blogs.technet.com/configurationmgr/
System Center – Data Protection Manager Team blog: http://blogs.technet.com/dpm/
System Center – Orchestrator Support Team blog: http://blogs.technet.com/b/orchestrator/
System Center – Operations Manager Team blog: http://blogs.technet.com/momteam/
System Center – Service Manager Team blog: http://blogs.technet.com/b/servicemanager
System Center – Virtual Machine Manager Team blog: http://blogs.technet.com/scvmm
The Forefront Endpoint Protection blog : http://blogs.technet.com/b/clientsecurity/
The Forefront Identity Manager blog : http://blogs.msdn.com/b/ms-identity-support/
The Forefront TMG blog: http://blogs.technet.com/b/isablog/
The Forefront UAG blog: http://blogs.technet.com/b/edgeaccessblog/