Microsoft® Exchange Server 2007: Implementation and Administration

Chapter 16. E-Mail Routing

E-mail routing in Exchange is like a colon in the human body. They both share a level of complexity that is often taken for granted and you only think about them on occasion (such as when messages stop flowing or you eat a bad burrito).

There have been a lot of improvements in how messages flow between Exchange Server 2007 mailboxes, including new features such as basing message flow between servers on Active Directory sites and improvements in message security when a message is transmitted.

In this chapter, I will uncover how e-mail routing works in Exchange 2007, how to con-figure Send and Receive connectors, and where to look when troubleshooting Exchange routing or searching for a particular message.

This chapter includes the following topics:

• Improvements in 2007

• How internal e-mail routing works

• Send connectors

• Receive connectors

• Logging

Improvements in 2007

Before we delve into how internal e-mail routing works, it's worth noting a few of the many improvements Exchange 2007 delivers in comparison to earlier versions of Exchange.

Prior to Exchange 2007, all messages were processed by the same server that connected MAPI clients, managed the information store, and hosted Outlook Web Access. This all-in-one approach worked well for many years, but it couldn't scale with the growing needs of organizations that had become increasingly dependent on their messaging systems. To remedy this, Microsoft abstracted all message processing and delivery functions into the ...