When migrating from Office 2010 to MSO 2013, for Exchange cached mode clients an existing OST file will be recreated and compressed: Source:http://technet.microsoft.com/en-us/library/cc179067.aspx#section6 "...when Outlook 2013 is installed and Cached Exchange Mode is enabled, a new compressed version of the Outlook data file (.ost) is created."
My question: will the new OST created out of the old one or by resynchronizing against the Exchange mailbox? I guess the upgrade procedure does the compression just locally on the pc (the second option would put too much load on the network when upgrading a larger number of clients). But I couldn't find a clear statement about that in any tech article.
Thank you in advance!
Regards, Joern