In creating an MRM Managed Folder Mailbox Policy to attempt to delete all contents of the Deleted Items Folder each time the Managed Folder Assistant runs, the value of 'Length of retention period in days' should be set to zero (0), yet the minimum value allowed is one (1). In Exchange 2003, via Mailbox Manager, you could specify 'Any' which would equate to zero (0) in Exchange 2007. Why is the minimum value for 'Length of retention period in days' one? Is there any way to get it to zero?

Per my research, there’s no method that can set the retention period less than 1 day in the exchange 2007 natively The only workaround is to export the items in the “Deleted items” folder regularlyJames Luo TechNet Subscriber Support (http://technet.microsoft.com/en-us/subscriptions/ms788697.aspx) If you have any feedback on our support, please contact tngfb@microsoft.com