Exchange calendar appointment unique identifier in .eml migrated from 2003 to 2010

Question

We are moving from Exchange 2003 to Exchange 2010. We have many calendar appointments that are stored as '.eml' files in 2003. Each of these .eml files has a unique identifier in it's filename, e.g. http://myserver/exchange/[email protected]/Calendar/123.eml

We have a program which stores these identifiers in a database, and then modifies the appointments by locating an appointment by it's unique identifier.

When we migrate this appointment to 2010, the calendar appointment is set up correctly. However, I would like to be able to access the appointment (via Exchange Web Services) by using the unique identifier that was specified in the .eml file in 2003.

Is the name of the .eml file migrated across to 2010? Can it be accessed as any property of the appointment?

Many thanks!

Martin

Answer 1

http://myserver/exchange/[email protected]/Calendar/123.eml is the DavHref property which is gone in 2010 and later. Before you migrate to Exchange 2010 you should convert your application to use another property (as once you do migrate there is no way of mapping between this old value) I would suggest having a read of https://msdn.microsoft.com/en-us/library/office/dn605828%28v=exchg.150%29.aspx which details the different identifiers. For calendar items PidLidGlobalObjectId https://msdn.microsoft.com/en-us/library/ee157690%28v=exchg.80%29.aspx is generally the best property to use as this is guaranteed not to change. You can't bind directly to an item using this property so you need to search then bind.

Cheers Glen