Exchange Server 2007 provides ActiveSync mailbox policies to allow administrators to manage the Windows Mobile devices that attach to the network. This allows you to apply a common set of policy or security settings to a group of users or even an individual user.
Exchange 2007 RTM included 16 policy settings. That number climbs to 27 in Exchange 2007 SP1 for the Exchange 2007 Standard CAL. The SP1 Enterprise CAL offers an additional 16 settings. Settings that only exist in the Enterprise CAL, such as controlling POP and IMAP, Bluetooth, WiFi, the camera and text messaging, make that CAL a compelling choice for some customers.
The Exchange Team blog has an in-depth explanation of ActiveSync policies, as well as a great chart that shows the different policies for each version and CAL. Read What's New for Exchange ActiveSync Mailbox Policies in Exchange Server 2007 SP1? Microsoft also has a policy reference on MSDN, Understanding Exchange ActiveSync Mailbox Policies. Keep in mind that these settings only apply to devices that support them. Some only work on Windows Mobile 6 and some mobile device vendors may strip support for them from their mobile devices.
Another important change in SP1 is that it now publishes a default EAS policy, where RTM requires you to manually apply the default policy.