Hi George,
How is work?
Where you set these limits depends on your situation, System Policy "limits" are applied to all mailboxes and information stores on all Exchange Servers in your Active Directory Forest/Exchange Organization (unless and information store or account had a separate limit set). So this is where you would set a general limit for all mailboxes in your exchange organization. If you needed to give certain users either a higher or lower limit then you would configure a limit at either the information store or AD account/Mailbox level, which would override the System Policy limit.
The order of precedence is:
System Policy
Information Store (setting here overrides a system policy setting)
AD Account/Mailbox setting (setting here overrides everything)
Regards
Ben Hoffman
Microsoft MVP - Windows Server System Exchange