I just started a migration from Exchange OnPrem to Office 365 and I have Citrix VDI for 70% of the users. I got some docs with Citrix and Microsoft recomendations where I´ll enable Cached Mode and use a network storage (folder) to store OST files and use Outlook GPO to configure the time of the cache ( for example a month or a week) . But I need to plan the size of storage that will be necessary to attend this. Do you have a best pratice on that ? Is there some powershell script to help me to determine the right size of these new OST files if I set cache mode to a week based on the size of current Exchange On Prem mailboxes or based on inbound and outbound traffic?