Microsoft will sometimes recommend Exchange Cached Mode when using Outlook to connect to Microsoft Exchange in order to improve the end users experience.   In this mode, a copy of the user's mailbox is downloaded into a .OST file.  The size and performance of this file did not traditionally make Exchange Cached Mode a good candidate for a non-persistent desktop environment. To address this issue, administrators configured Microsoft Outlook to use "Online Mode."  With this configuration, the users email is not cached.  

Starting with App Volumes 2.14, the .OST file is now redirected automatically to the Writable Volume.  No additional configuration is required.  The administrator can enjoy the benefit of managing a non-persistent desktop, while the user enjoys the benefit of Exchanged Cached Mode.

Note:  If .OST file redirection is also configured in VMware's User Enviroment Manager (UEM), Outlook will defer to the policy defined in UEM.

Microsoft Search Index provides the ability for a user to quickly locate data without having to search through every single item stored in a users mailbox.  

Starting with App Volumes 2.14 the Microsoft Search Indexes are also automatically placed in the Writable Volume.