Note: This article is based on a pre-release product and may therefor be subject to changes.

Here’s an short list of the changes and notes regarding Exchange 2013, compared to Exchange 2010:

Goodbye EMC, Hello EAC
The Exchange Management Console (EMC) is no more. A new web-based management interface, the Exchange Administration Center (EAC), replaces EMC and ECP (organization management functions). The EAC provides a single console for on-premise, hybrid or online deployments and doesn’t require installation of management tools.

EAC can also be used to manage Public Folders and contains functionality to run reports on mailbox or administrator audit logs.

Less roles is more
Exchange 2013 reduces the number of Exchange server roles to two: Client Access Front End server and Mailbox server (Exchange 2003 Front-End/Back-End anyone?):

• Client Access Front End servers will only proxy or process client traffic. They consist the known Client Access Server services as well as the Front End Transport Service component that deals with mail transport, hence the term Client Access Front End or CAFE. Multiple CAFE servers can still be organized in Client Access Arrays. New in Exchange 2013 is that client connections are stateless, which means you can utilize simple layer 4 (based on IP address or port) load balancing solutions or DNS Round Robin when requirements permit. Since connections are stateless, I expect client experience to improve as well as clients shouldn’t notice when being failed over to a different CAS server;
• Mailbox servers are used for data storage and UM. Multiple Mailbox servers can still be organized in clusters using Database Availability Groups.

If you require an Edge Transport server, you can use Exchange 2010 or even Exchange 2007 Edge Transport servers in combination with Exchange 2013.

Transport Servers MIA?
In Exchange 2013, mail flow is dealt with by both the Client Access server and the Mailbox server. The Client Access server hosts a service called Front End Transport service which will process messages from or to external sources. The Mailbox server hosts two transport-related services, Hub Transport and Mailbox Transport service, which will process messages from or to other Mailbox servers or deal with the retrieval or storage of messages.

Because the transport services are now co-located with Mailbox and Client Access servers, I do foresee challenges for organizations who designed infrastructure and farms purely for routing and processing messages. Of course, Mailbox servers will perform the same job, next to serving mailboxes, but this defeats the best practice of reducing attack surface by splitting roles.

This architecture found in Exchange 2010 didn’t exist in Exchange 2003 (but could come a long way by hardening servers). Then came Exchange 2007 with its server role architecture, which made a lot of sense for large environments (of course, there’s always the option of co-locating server roles). Now, wtih this reduction of server roles, I know at least 1 customer who will ponder on creating hardening guides for Exchange 2013 when the time comes.

Au revoir, MAPI
MAPI (RPC) will be dropped in Exchange 2013, leaving Outlook Anywhere (RPC over HTTPS) access as the protocol of choice for clients (IMAP/POP access still there). This means less holes to put in firewalls (only HTTPS), easier load balancing configurations, a single client endpoint (which also has benefits from a certificate perspective), etc. Of course there are also downsides, like Outlook 2003 doesn’t work and tools may stop working.

Public Folders
Unlike Exchange 2010, where Microsoft in early announcements mentioned the possible deprecation of Public Folders, Microsoft leaves no doubt when it comes to Public Folders and Exchange 2013. In fact, Microsoft made some interesting changes to the Public Folders architecture, where Public Folders reside in mailbox databases utilizing mailboxes (i.e. Public Folder Mailboxes).

This architectural change enables Public Folders to basically have the same benefits as Mailboxes in Mailbox databases, e.g. cluster continuous replication better known as Database Availability Groups. While this has serious implications for the migration scenario, it might prove a better alternative the “move to Sharepoint” cliché. It also requires rethinking placement of mailbox databases; while public folders utilize a multi-master model, where a branch office could make changes in local public folder database which replicated throughout the organization, Database Availability Groups utilizes a single master model, meaning with Exchange 2013 public folder clients must connect to the writable mailbox database copy.

The feeling that Microsoft is serious again about Public Folders is also driven by the fact that the next version of Exchange Online, part of the next version of Office 365 which confusingly is called Office 365 Preview, contains Public Folders. That’s right, Public Folders in Office 365; who thought that would ever happen, raise your hands. Check out Office 365 Preview here.

Outlook Web Access support for Exchange 2013’s Public Folders is expected in Exchange 2013 SP1.

Storage Engine
Exchange 2013 sticks with the ESE as the database engine of choice. The Information Store processes, now called Managed Store, have been revised, utilizing per database processes which enable faster fail-over and improved resilience. The engine integrates Microsoft’s FAST indexing engine.

Additionally, Microsoft expects another 50% IOPS reduction (which would mean 1/8th of Exchange 2003 figure) and support for 8TB SATA disks which are expected to become available later this year.

DAG 2.0
Well, sort of. Exchange 2013 adds functionality to the Database Availability Groups. To enhance site resiliency, servers can be in different locations, meaning you you aren’t required to place CAS servers in the Active Directory site together with the Mailbox servers. This creates interesting scenarios, where for example you could create (centralized) CAS farms (even in dedicated sites), while the DAGs are hosted in other sites. Major benefit of this is also that this reduces the namespaces required to create a resilient Exchange configuration.

Certificates
Client Access servers deal with certificate management; Mailbox servers contain self-signed certificates which are automatically trusted. The EAC contains a notification center which will report on certificates nearing expiration.

Data Loss Prevention
Here, Data Loss doesn’t refer to loss of bits, but to loss of sensitive information. Exchange 2013 provides a mechanism to protect sensitive data. Supported clients, like Outlook 2013, provide notifications of possible policy breaches through PolicyTips, much like MailTips. More information on DLP here.

OWA 2013
Outlook Web App (OWA) in Exchange 2013 adds integrated apps, like Bing Maps. Apps can be managed using the EAC. Apps installed in Outlook 2013 also become available in OWA 2013 and vice versa. OWA 2013 also offers LinkedIn integration and merged calendar view (like in Outlook).

OWA 2013 supports the following browsers when compared to OWA 2010:

• Windows
  • Internet Explorer 7 or later (same);
  • Firefox 12 or later (was Firefox 3.0.1+);
  • Chrome 18 or later (was Chrome 3.0.195.27+);
  • Safari 5.1 or later.
• Mac
  • Firefox 12 or later (was 3.0.1+);
  • Safari 5.0.6 or later (was 3.1+);
  • Chrome 18 or later.
• Linux
  • Firefox 12 or later (was 3.0.1+);
  • Chrome 18 or later.
• Tablets & Smartphones
  • Windows 8 PRE;
  • iOS 5.0 or later for iPhone or iPad;
  • Android 4.0 or later;
  • Other browsers revert to Light mode

Note: iPad 1 has 256 MB, OWA 2013 requires 512 MB therefor it isn’t supported on iPad1 devices.

When using compatible browsers OWA 2013 supports offline mode, which means you can read or compose messages while disconnected, using your system to store the information. More information on which platform / browser combinations supports offline mode can be found here.

eDiscovery
Recently, Microsoft announced it was no longer required to have an Enterprise CAL to perform Multi-Mailbox Searches in Exchange 2010. Like some predicted this was a clue on changes in Exchange 2013, which not only allows for cross-platform against Exchange, Lync and Sharepoint (In-Place eDiscovery), but allows you to export mail contents to PST files.

You can also search across primary and archive mailboxes in OWA.

Compliance
Also, Legal Hold, now known as In-Place Hold, can now be performed based on queries and can be bound to a certain timeframe as well in Exchange 2013.

Unified Messaging
In Exchange 2013, UM functionality is split between CAS and Mailbox servers which explains the absence of the UM server role. The CAS server deals with call routing, while the Mailbox server provides UM services like synthesis.

Based on UCMA 4.0, Exchange 2013 UM utilizes the same engine for text-to-speech (TTS) and automatic speech recognition (ASR). The generated grammar files, previously generated and stored per server, are generated by the Mailbox Assistant running on the Mailbox server hosting the arbitration mailbox. The speech grammar files are stored in the arbitration mailbox and can be downloaded by Mailbox servers.

When trying to resolve the Caller ID, Exchange 2013 UM will consult different sources besides the default contacts folder, like other contact folders and social networks.

Updated MRS
The Mailbox Replication Service (MRS) has been updated in Exchange 2013 to enable bigger parallel moves, providing progress reports using notifications and to make the process more resilient by automatic retries and move priorization.

Site Mailboxes
Exchange 2013 introduces a new concept called Site Mailboxes, which bind an Exchange mailbox to a Sharepoint site. Goal is to enable users to collaborate easier, by enabling site members to utilize a single interface to access documents as well as related messages. More information on Site Mailboxes here.

PowerShell 3.0
The Exchange Management Shell is now based on WinRM 3.0.

Miscellaneous
Other changes worth mentioning:

• Lync 2013 can archive contents in Exchange 2013 and use it to store contacts;
• Exchange Workload Management, more information here.
• To skip the license screen during (unattended) setups, you can use the switch IAcceptExchangeServerLicenseTerms with setup.exe, e.g.
  Setup /m:Install /r:C,M /OrganizationName:X /IAcceptExchangeServerLicenseTerms