How Messages Route Within an Internal Exchange Environment

Internal messages are routed through Exchange in a similar manner. The process for a mail user to send a message to another mail user in the organization or to the Internet is as follows:

1. A message is created by a user in Outlook, on their Windows Mobile device, or on OWA where the user is connected to the Client Access server.

2. The message is stored on the user’s Mailbox server as an Outbox message and, likely, a copy is stored in the user’s Sent Items folder on the Mailbox server.

3. The Mailbox server then typically sends the message to a Hub Transport server that performs compliance content assessment and then looks at the internal routing for messages and forwards the message to another Hub Transport server, directly to a Mailbox server, or out to the Internet.

4. For internal messages, the Mailbox server places the incoming message into the user’s mailbox and notifies the user that a message has arrived.

5. The message recipient launches Outlook, OWA, their Windows Mobile device, or another client system and connects to the Client Access server. The Client Access server confirms the destination point of the user’s mailbox and provides the user access to their mailbox data.