This is not a new topic and has been discussed for quite some time.
Exchange ActiveSync mailbox policies let you apply a common set of policy or security settings to a user or group of users. The following table summarizes the settings you can specify using Exchange ActiveSync mailbox policies.
Everything is ver well detailed in :
Understanding Exchange ActiveSync Mailbox Policies: Exchange 2010 Help
However, I wanted to make sure the following part would be seen 🙂
If you have Windows Phone 7 mobile phones in your organization, these phones will experience synchronization problems if certain Exchange ActiveSync mailbox policy properties are configured. To allow Windows Phone 7 mobile phones to synchronize with an Exchange mailbox, either set the AllowNonProvisionableDevices property to “TRUE” or only configure the following Exchange ActiveSync mailbox policy properties:
In the referred page you will be able to observe other links to very useful articles such as :
Understanding Direct Push: Exchange 2010 Help
Understanding Exchange ActiveSync Reporting Services: Exchange 2010 Help
Understanding Mobile Device Management: Exchange 2010 Help
Hope you have a good reading.