You can view the "Software Update Description (also known as Software Update Notes)" within the Control Center using the "View Description" button (Administration > Version > Updates).
This button will not be active if you did not see the new version in the Control Center. In that case, you can make that button active by clicking "Check for Updates" button to make the new version visible. If this behavior sounds confusing, it's because of a new feature called "Staggered update notifications". Here is the information about this feature in the release notes:
QUOTE:
The Symantec Brightmail Gateway Control Center displays (and can deliver) update notifications
to customers when new software is available for download. Starting as a new feature with
Symantec Brightmail Gateway 9.0, Symantec has a rolling notification process. Customers are
incrementally notified of a new update over several weeks between the software release date
and the general availability (GA) date. If you learn of a new software update but have not received
a notification, you can check for an update before receiving an update notification. In the
Control Center, click Administration > Hosts > Version > Updates > Check for Updates. If an
update is available, you can download and install the update. Not receiving a notification right
away is not a problem, and there is no need to contact Technical Support.
UNQUOTE:
You can view the SBG 9.0 Release Notes in the following KB article:
http://service1.symantec.com/SUPPORT/ent-gate.nsf/docid/2010020114554754
Other SBG 9.0 documentation including the Release Notes are available in PDF form from the following link:
http://www.symantec.com/business/support/documentation.jsp?language=english&view=manuals&pid=53991
Regards,
Adnan