Exchange 2013 Server Roles in short note

We all know Microsoft Exchange Server 2013 released with only two server roles as Mailbox Server Role and Client Access Server. Other server roles components from Hub Transport Server and Unified Messaging Server are now included with MB and CAS server roles. In this post we will see those Server roles functions in short note.
Mailbox Server Role:

Mailbox Server Role in Exchange server 2013 has the components like Client Access Protocols, the mailbox database, the transport service and unified messaging components. So the Mailbox Server role in Exchange 2013 now functions as a legacy Mailbox Server Roles, Hub Transport Server Role, Unified Messaging Server Role and part of Client Access Server role. Mailbox Server Role in Exchange Server 2013 perform the below functions

1. Provides Client Access features for Exchange 2013 clients
2. Responsible for all means of Internal Mail flow and process the external inbound\outbound emails to Front End Transport Service in Client Access Server
3. Hold the Mailbox Databases and Public Folder Mailboxes
4. Responsible for Unified Messaging functionality (CAS redirects the SIP traffic from incoming emails to Mailbox Servers

Note: if we are separating the server roles installation then the mailbox server role has to be first server role which has to be installed first.
Client Access Server Role:

The Client Access Server provides authentication, limited redirection and proxy services to all client Access Protocols like http, pop and imap, and SMTP. The client access wont process any emails, it is a thin and stateless server which won’t do any data rendering and it won’t queue or store any emails in CAS server.
As mentioned above Client Access Server role has 3 components

• Client Access Protocols
• SMTP
• UM Call Router

CAS server is an Exchange aware Proxy Server and it supports the Proxy and Redirection logic for Client Protocols.

Posted in: Exchange Server 2013