This content is part of the Essential Guide: Plan your Exchange migration to Office 365 with confidence

Microsoft Exchange Server

Microsoft Exchange Server is Microsoft's email, calendaring, contact, scheduling and collaboration platform deployed on the Windows Server operating system for use within a business or larger enterprise.

Microsoft designed Exchange Server to give users access to the messaging platform on smartphones, tablets, desktops and web-based systems. Telephony capabilities in Exchange Server support voice messages. Exchange users collaborate through calendar and document sharing. Storage and security features in the platform let organizations archive content, perform searches and execute compliance tasks.

Understanding Exchange Server 2016

Exchange Server 2016 features two server roles: the edge transport server and the mailbox server. This change simplified the deployment and management of the Exchange Server infrastructure to allow for greater scalability, hardware utilization and resiliency.

The edge transport server protects the organization from attacks. The administrator deploys it outside the corporate firewall to handle all internet-facing message traffic. The edge transport server provides centralized control over message flow to secure the system from spam and malware. It also runs transport rules to direct message flow in and out of the Exchange Server system.

Understand what's changed in the
Microsoft Exchange Server architecture.

In March 2017, Microsoft announced it would deprecate the edge transport server role on Windows Server 2016 systems due to technical conflicts, but said the role will continue to work on other supported Windows Server systems.

The mailbox server role combines the mailbox and client access roles that had been separate in earlier Exchange Server versions. Client access functionality runs authentication, some redirection and proxy services with client protocols, such as HTTP, Post Office Protocol, Internet Message Access Protocol and Simple Mail Transport Protocol. Client access handles security and messaging data transfers. Mailbox functionality controls the active mailbox content and management, such as supporting client access protocols, transport services, mailbox databases and unified messaging functions.

Exchange Server 2016 features

Exchange Server 2016 adds several new features to the Exchange Server line. In addition to consolidated server roles for simpler and more scalable deployments, Microsoft added integration with Exchange Online to allow a hybrid messaging platform. This arrangement can benefit an enterprise that may not be able to perform a full migration to Exchange Online for regulatory or technical reasons.

A strong emphasis on mailbox search capabilities makes it easier for users to find and work with content of interest. Data loss prevention features help administrators recognize and protect sensitive information. Messaging policies, archiving, hold and auditing features provide better message content handling for regulatory and compliance purposes.

Exchange Server versions

Microsoft released Exchange Server as a major product as version 4.0 in 1996. Since then, it has evolved through dozens of major updates. The following list shows the version progression of Exchange Server with the corresponding release date and software build:

  • Exchange Server 4.0 Standard Edition was first released June 11, 1996, as build 4.0.837.
  • Exchange Server 5.0 was first released May 23, 1997, as build 5.0.1457.
  • Exchange Server version 5.5 was first released Feb. 3, 1998, as build 5.5.1960.
  • Exchange 2000 Server was first released Nov. 29, 2000, as build 6.0.4417.
  • Exchange Server 2003 was first released Sept. 28, 2003, as build 6.5.6944.
  • Exchange Server 2007 was first released March 8, 2007, as build 8.0.685.25.
  • Exchange Server 2010 was first released Nov. 9, 2009, as build 14.00.0639.021.
  • Exchange Server 2013 was first released Dec. 3, 2012, as build 15.00.0516.032.
  • Exchange Server 2016 was first released Oct. 1, 2015, as build 15.01.0225.042.
  • The latest version of Exchange Server 2016 is Cumulative Update 6 (CU6), which was released June 27, 2017, as build 15.01.1034.026.

Exchange Server 2016 requirements

Exchange Server is complex, enterprise-class software that is typically deployed across several data centers and utilizes enterprise storage and core services, such as Active Directory (AD).

At the hardware level, Exchange Servers require x64 architectures with Intel or AMD 64-bit processors -- Itanium IA64 processors are not supported. A mailbox server needs at least 8 GB of memory, while an edge transport server requires at least 4 GB. For storage, the requirements are New Technology File System formatted disks with at least 30 GB for the Exchange installation, 500 MB for the message queue database, 200 MB on the system drive and 500 MB for each unified messaging language. Disk paging must be equal to physical memory plus 10 MB -- up to 32 GB. Resilient File System formatted storage can only be used for log files, mailbox database and content indexing partitions.

At the operating-system level, Exchange Server 2016 mailbox or edge transport servers require Windows Server 2016 Standard or Datacenter editions, Windows Server 2012 R2 Standard or Datacenter editions, or Windows Server 2012 Standard or Datacenter editions. Administrators can use management tools on the 64-bit client operating systems, such as Windows 8.1 and Windows 10. Exchange Server should run on the latest version of Microsoft's .NET Framework.

The 64-bit AD domain controllers should use Windows Server 2008 Standard, Enterprise, Datacenter -- or later -- operating systems. The AD forest must be set for Windows Server 2008 or higher. Domain name system namespaces must be contiguous, noncontiguous, single-label domains or disjoint. IPv6 is only supported when IPv4 is installed and running on a network that supports both formats.

The requirements for Exchange Server are extensive and vary depending on the roles installed, the use of virtualization and other factors. Administrators should always refer to the latest Exchange documentation for requirements, preparation and installation guidance.

Exchange Server 2016 availability

Exchange Server 2016 has several important features to maintain resilience and availability. Mailbox servers rely on database availability groups (DAGs), which comprise a group of mailbox servers that host databases for automatic recovery from database, network or server failures. Organizations can span a DAG across multiple AD sites for cross-site resilience.

Resilience features are incorporated in the message transport process. Shadow redundancy copies all messages in transit, while the safety-net feature makes redundant copies of all delivered messages.

Exchange Server clients

Exchange users access and interact with messages through an email client. Microsoft Outlook is the most common client. Exchange Server 2016 supports Outlook 2016, Outlook 2013, Outlook 2010 SP2 -- with updates -- Outlook for Mac for Office 365 and Outlook for Mac 2011.

Outlook is also available as a web-based application, called Outlook on the web -- formerly Outlook Web App and commonly abbreviated to OWA -- for users to access and interact with messages from many different web browsers, such as Microsoft Edge, Internet Explorer 11, and the latest versions of Mozilla Firefox, Google Chrome and Apple Safari. Outlook on the web lets users link and share documents stored in OneDrive for Business in an on-premises SharePoint Server -- a simpler and more direct way to save and attach files to emails.

Microsoft Exchange Online

Microsoft offers Exchange as a SaaS offering called Exchange Online. It is available as a stand-alone service or part of the Office 365 suite. End users connect to Exchange Online through the Outlook client or Outlook on the web. Administrators with Office 365 admin permissions configure and manage the service. Microsoft offers Exchange as a hosted service to reduce the administrative work involved with on-premises Exchange deployments.

Organizations pay a recurring fee -- per user, per month -- for Exchange Online either as a stand-alone offering or as part of an Office 365 bundle. There are two stand-alone plans. Exchange Online Plan 1 -- $4 per user, per month -- offers secure and available business email, with a 50 GB mailbox per user. Exchange Online Plan 2 -- $8 per user, per month -- builds on Plan 1 and includes unlimited storage, hosted voice mail and data loss prevention functionality.

This was last updated in August 2017

Continue Reading About Microsoft Exchange Server

Dig Deeper on Windows Server operating systems

Join the conversation

1 comment

Send me notifications when other members comment.

Please create a username to comment.

What are some challenges administrators who are new to Exchange Server might face?


File Extensions and File Formats