What is Exchange ActiveSync?

Exchange ActiveSync (EAS) is an XML-based protocol that communicates over HTTP (or HTTPS). Exchange ActiveSync is designed for the synchronization of email, contacts, calendar, and tasks from a messaging server to a mobile device. The protocol also provides mobile device management and policy controls.

Exchange ActiveSync Features

Exchange ActiveSync has the following features:

* Support for HTML messages
* Support for follow-up flags
* Support for fast message retrieval
* Meeting attendee information
* Enhanced Exchange Search
* Windows SharePoint Services and Windows file share (UNC) document access
* PIN reset
* Enhanced device security through password policies
* Autodiscover for over-the-air provisioning
* Support for setting auto-replies when users are away, on vacation, or out of the office
* Support for tasks synchronization
* Direct Push

Device Security Features in Exchange ActiveSync

In addition to the ability to configure security options for communications between the Exchange server and your mobile phones, Exchange ActiveSync offers the following features to enhance the security of mobile phones:

* Remote wipe: If a mobile phone is lost, stolen, or otherwise compromised, you can issue a remote wipe command from the Exchange Server computer or from any Web browser by using Outlook Web App. This command erases all data from the mobile phone
* Device password policies: Exchange ActiveSync lets you configure several options for device passwords. These options include the following

Exchange ActiveSync 12.1

Exchange ActiveSync 12.1 came in Exchange Server 2007 SP1. This version of the protocol was one of the largest changes since version 2.5. Exchange ActiveSync 12.1 featured header compression (Base64 encoding of a binary structure) to decrease the amount of data sent wirelessly. It also featured a multiple collections sync (a bundling of all sync requests together instead of the previous way of doing a sync for each folder separately), a hanging sync which allowed the server to keep a communications channel open to the client all time so battery life and data wouldn’t be consumed constantly turning on the radio and querying the server and a “true push sync” solution which had far lower message delivery latencies, as opposed to the previous ping based “push to pull” solution), a confirmation of a completed remote wipe.

Exchange ActiveSync 14.0

Exchange ActiveSync 14.0 was introduced as part of Exchange Server 2010. This new Exchange ActiveSync added a new conversation view that put email messages in a view connected by several attributes including a message ID and the email subject, notes syncing. Exchange ActiveSync 14.0 has the ability to look up the availability (free/busy status) of a contact (from their calendar), a Nickname Cache which shared the names of commonly used contacts between Outlook Web App (OWA) and EAS. It also features the ability to set a server side rule to always move messages in a conversation, lunar calendar support, syncing of the reply state (which let the device and the server know if any message had been forwarded or replied to from any other source), a new way to identify Unified Messaging (UM) messages. Thus, making it easier to manage the voicemail that appeared in a user’s inbox. This is also the first version of EAS that identified clients that were using older versions of EAS and alerted them if there was an updated version of the client that would enable newer features.

Exchange ActiveSync 14.1

Exchange ActiveSync (EAS) 14.1 came as part of Exchange Server 2010 SP1. This version of the protocol added GAL photo (images stored in an Active Directory server of the user who has sent the email), Message Diffs (a means of sending only the new portion of an email and avoiding redundant information), added device/user information to the provision command so that the new Allow/Block/Quarantine feature could more easily allow administrators to control which devices should be connected to their organizations, and Information Rights Management (IRM) over EAS (a method to apply digital rights management control and encryption to email messages that are sent and received).