How Messaging servers work

Common components of most messaging systems include the following:
A message transport system that moves messages from one place to another. Examples include the Simple Mail Transport Protocol (SMTP).
A message storage system that stores messages until a user can read or retrieve them. Messages may be stored in a client/server database, a shared fle database, or even in individual fles.
A directory service that allows a user to look up information about the mail system’s users, such as a user’s email address in Active Directory.
A client access interface on the server that allows the clients to get to their stored messages. This might include a web interface, a client/server interface, or the Post Offce Protocol (POP).
The client program that allows users to read their mail, send mail, and access the directory. This may include Outlook, Outlook Web App, and a mobile device such as a Windows Phone, an iPhone, or an Android device.

Most organizations that deploy an email system usually deploy additional components from their email software vendor or third parties that extend the capabilities of the email system or provide required services. These include the following:

Integration with existing phone systems or enterprise voice deployments to pull voice messages into the mailbox
Message-hygiene systems that help reduce the likelihood of a malicious or inappropriate message being delivered to a user
Backup and recovery, disaster recovery, and business continuity solutions
Message archival software to allow for the long-term retention and indexing of email data
Electronic forms routing software that may integrate with accounting, order entry, or other line-of-business applications
Mail gateways to allow differing mobile devices, such as BlackBerry devices, to access the mail server, along with native access through Exchange ActiveSync
Email security systems that improve the security of email data either while being transferred or while sitting in the user’s mailbox
A link load balancer to balance the load between multiple Internet-facing servers or internal servers

What Is Exchange Server?


In its simplest form, Exchange Server provides the underlying infrastructure necessary to run a messaging system. Exchange Server provides the database to store email data, the transport infrastructure to move the email data from one place to another, and the access points to access email data via a number of different clients.
However, Exchange Server, when used with other clients such as Outlook or Outlook Web App, turns the “mailbox” into a point of storage for personal information management such as your calendar, contacts, task lists, and any file type.

Public folders look like regular mail folders in your mailbox, except that they are in an area where they can be shared by all users within the organization.

The Unifed Messaging features in Exchange Server 2013 further extend the functions of Exchange Server in your organization by allowing your Exchange Server infrastructure to also act as your voicemail system and direct voicemails and missed-call notifcations automatically
to the user’s mailbox.

Many Modes of Access

Exchange Server 2007 move away from RPC in client connectivity in favor of RPC over HTTPs, also known as Outlook Anywhere.

Exchange Control Panel (ECP), which gives users a much greater degree of control over their mailbox, contacts, and group memberships. ECP is now built into the Outlook Web App interface.

Another signifcant feature of Outlook Web App is the ability to use the web-based interface when working offline and completely disconnected from the network.
With Exchange Server 2013, Exchange ActiveSync (EAS) continues to offer signifcant partnerships with and control over mobile devices.