Introduction

In Exchange 2013, SP1 (CU4) the Edge Transport was reintroduced. We got the Edge Transport role in SP1 together with the CAS and Mailbox. In Exchange 2013, the CAS server is stateless, which means that by default it does not have any queue data; the queue is moved and placed on the Mailbox server, however, this can be changed. A benefit of the new architecture is that it is easier to manage and scale out the Exchange environment. The SMTP frontend service scales are based on a number of connections, which means if you need more servers, then you can scale out easily by adding more servers.

Exchange 2007 and 2010 Edge Transport server are supported to work together with an Exchange 2013 Mailbox server, for example, in EdgeSync.

In addition to routing messages, you can apply rules, configure settings, and enforce limits on messages as they pass through the servers in your environment. Transport agents can be used to provide basic anti-spam protection, and both roles implement detailed...