Google Message Security for Google Apps Administration Guide - Manual (Page 135)

The Message Center 135
By default, your service automatically deletes virus-infected messages, so
users won't see any messages in the Virus quarantine. You can change this
setting, but we recommend that you leave it as is.
The Virus quarantine can also let users safely review the content of
messages, without risking harm to their computers. However, if message
archiving is turned on (it's On by default), users can't view message content,
to prevent virus-infected messages from being stored in your archive.
• Pending Quarantine: This lists messages that are blocked from a user's
Inbox, because they may contain a recently discovered virus (often called
“zero-hour” viruses) or other threat. Users receive an Early Detection
notification whenever there are messages in this quarantine.
By default, the Pending quarantine does not appear in the Message Center.
You can change this setting, but we recommend that you leave it as is.
The Pending Quarantine can also let users safely review the content of
messages, without risking harm to their computers. However, if message
archiving is turned on (it's On by default), users can't view message content,
to prevent virus-infected messages from being stored in your archive.
• Personal Archive: This stores a copy of each message that a user sends or
receives for the retention period you purchased (the standard period is 90
days). With the Personal Archive, users can search for and recover their
email messages, even if they’ve permanently deleted them from their
inboxes.
• Personal settings: In Message Center, users can access their personal
settings to change their own filter levels and add their own approved and
blocked senders.
Enable / Disable Message Center Access
You enable users’ access to the Message Center, under User Access, which is
available both for the default user and for individual users.
• Enable or disable access for all new users you have not yet added via the
org’s Default User template.
• Temporarily disable access for a particular user via user-level User Access
settings.