Google Message Continuity Setup and Administration Guide - Manual (Page 6)

8 Google Message Continuity Setup and Administration Guide
How Synchronization Works
The diagram below displays the different components of Google Message
Continuity:
1. Postini filters inbound messages for spam, viruses, and other malicious
content.
2. Postini dual-delivers inbound messages to Gmail and Microsoft Exchange.
3. Users access their email through both Exchange and Gmail. When Exchange
is unavailable, users can access their mail through Gmail.
4. The Sync Server synchronizes changes made in both Gmail and Exchange.
Before, during, and after an outage, Message Continuity does the following:
Normal Operation Before an Outage
Postini filters inbound messages for spam, viruses, and other malicious content,
and delivers mail to both Exchange and Gmail accounts using Postini Dual
Delivery. The Continuity Sync Server synchronizes outbound and intradomain
mail between Exchange and Gmail. As users read and modify their Exchange
mail, changes are synchronized with Gmail.
During an Outage
During an outage event, Postini spools inbound email destined for the Exchange
Server and delivers the mail to Gmail. During the outage, users can continue to
access their messages via Gmail.
After an Outage
Once the Exchange Server is back up, Postini unspools inbound email that was
destined for the Exchange server. Meanwhile, the Continuity Sync Server updates
the Exchange server with intradomain and outbound email changes, as well as
state changes made during the outage.