We have built a custom CRM tool that integrates with Exchange 2010 using Exchange Web Services. The issue we are encountering revolves around editing appointments through the CRM tool that were created in exchange 2003.

We have migrated the sales staff from Exchange 2003 to 2010 so that we could use EWS. EWS works great except for appointments that were created prior to the migration. Those appointments created prior to the migration in Exchange 2003 cannot be modified using EWS.

The reason is that the ExchangeItemUID for the appointment changed from 32 characters to 64 characters. EWS does not recognize ExchangeItemUIDs that are 32 characters. We are looking for a solution that will allow us to modify these appointments.

We are open to ideas of running a script that will update all appointment events for the sales people so that 2003 appointments are converted to 2010 format.

We are also open to alternate IDs as opposed to using UID. I have seen some references to using CleanGlobalObjectID, but I don't see that property in EWS.

Has anyone encountered this problem before? Any help you could give would be greatly appreciated!