In addition to your Google Apps Premier account you can enable Postini Standalone Filtering for greater spam fighting control. From the Google Apps control panel, you can configure Email settings for each organization in your domain. For example, you can set up multiple Content compliance and Objectionable content settings, and tailor these settings for a specific organization or sub-organization.

To add an email setting for an organization:

1. Sign in to the Google Apps control panel at https://www.google.com/a/cpanel/domain.com
2. Then enter your username and password to open the control panel.
3. From the menu at the top of the page, select the Settings tab.
4. From the left-navigation menu, click Email.
5. From the Email settings page, click Filters.
6. In the Organizations section near the top of the page, highlight the organization for which you want to add settings.
7. To create a new setting, click the Add Setting button near the right edge of the window (the Add setting dialog box opens).
8. Click the type of setting in the left navigation menu of the dialog box — for example, Objectionable content or Content compliance.
9. For detailed instructions on adding specific types of settings, see the following:

   Content compliance
   Objectionable content
   Append footers
   Approved sender lists
   Blocked sender lists
   Attachment compliance
   Restrict email delivery

10.  When you are finished making changes, click Add Setting.Note: Any settings you add or edit will be highlighted in yellow-orange on the Email settings page.
11. Click Save changes at the bottom of the Email settings page.

Additional Resources
What’s the difference between Postini integrated and standalone?
Postini Transition to Google Apps Email Security: Administration Guide