ZCS Administrator Guide 7.2.1

Open Source Edition

Zimbra Proxy Architecture and Flow

The following sequence shows the architecture and flow of Zimbra Proxy.

1.	End clients connect to Zimbra Proxy using POP/IMAP ports or HTTP requests to a backend server.

2.	When Zimbra Proxy receives an incoming connection, the Nginx component sends an HTTP request to the Zimbra Proxy Route Lookup Handler component.

3.	Zimbra Proxy Route Lookup Handler locates the route information for the account being accessed and returns this information to Nginx.

4.	The Memcached component stores the route information for the configured period of time. By default, this time is one hour. Nginx will use this route information until the default period of time has expired, instead of querying the Zimbra Proxy Route Lookup Handler.

5.	Nginx uses the route information to connect to Zimbra Mailbox.

6.	Zimbra Proxy connects to Zimbra Mailbox and initiates the mail proxy session. The end client behaves as if it is connecting directly to Zimbra Mailbox.