My company is ready to move from Exchange 2003 to Exchange 2010. Discussing potential risks of migration we couldn’t find the answer on the question “what will happened with the Calendar EntryID’s during the migration”. These ID's are used for the sync with the calendar of our LOB and they are stored in the DB of our LOB. If the EntryID’s will change then the next time synchronization is started all the calendar entries in our LOB will be doubled.
So my question is: “What will happened with the Calendar EntryID’s during the migration from Exchange 2003 to Exchange 2010?”