Google Message Archiving Administration Guide - Manual (Page 30)

Introduction 31
Quarantined Inbound Messages
If your message security service quarantines an incoming message, your email
server does not journal that message, and that message is not archived.
However, if a user or administrator views a message in a quarantine without
delivering it to his or her inbox, Message Archiving then captures the message
directly and stores it in the archive. If a user or administrator delivers a
quarantined message to his or her inbox, your email server journals the message
normally and sends it to the archive. Note that if a user or administrator first views
the message and then delivers it, Message Archiving stores only one copy of that
message.
WARNING: Keep in mind that if you view or forward mail from the junk quarantine,
then that junk mail is archived.
You cannot view or forward mail from the virus quarantine.
Quarantined Outbound Messages
Your email server journals all outbound messages before they reach the Postini
data center. Therefore, if you use Postini Outbound Services, and a user’s
outbound message is quarantined, Message Archiving still receives a copy of the
journaled message from your email server and archives it. If an administrator
views or delivers the quarantined message, another copy of the message is
archived.
WARNING: Keep in mind that if you view or forward mail from the junk quarantine,
then that junk mail is archived.
You cannot view or forward mail from the virus quarantine.
Duplicate Journaled Messages
In most cases, your email server journals only one copy of a message. For
example, Microsoft Exchange Server journals only one copy a message that a
user sends to multiple recipients or that multiple users receive. For details about
duplicate message handling during the journaling process, refer to your email
server’s documentation and support resources.
If you set up journaling on two or more email servers, multiple servers might
journal a separate copy of the same message. To handle these cases for
Exchange Servers, Message Archiving includes a feature called Exchange
Duplicate Suppression. With this feature, Message Archiving parses all journals
before storing the messages in the archive. To suppress duplicates, an
Exchange-journal fingerprint, based on the the information received in each
journal (including the original message binary, and the ordered list of sender &
recipients), is taken during indexing, and this fingerprint is stored as metadata in
the index.
When a query is issued for a customer with Exchange Duplicate Suppression
enabled, the Message Archiving service identifies the messages with identifical
fingerprints and returns only one result for the messages determined to be exact
duplicates. The duplicate messages do not appear in search results, nor in
exported results sets.