Exchange ActiveSync
Encyclopedia
Exchange ActiveSync is an XML
-based protocol that communicates over HTTP (or HTTPS
) designed for the synchronization of email, contacts, calendar, tasks and notes from a messaging server to a mobile device. The protocol also provides mobile device management
and policy controls.
) to Exchange 2000 servers syncing Email, contacts, and calendar and allowed users to select a folder list to sync but this was only for email folders (not contacts or calendar). This initial version of EAS has the user’s device “pull” data down rather than have the server “push” new information as soon as it was available.
) was the technology used to deliver this information to the device. Because of the use of SMS as a notification, the configuration of an SMS gateway was required and each account needed to be configured with a user’s mobile phone number.
) search was added to enable people to look up other co-workers in their company directory to find their email address. The ability to remotely wipe a device was also added so administrators could remove company data from a device that was lost, stolen, or after an employee left the company. Tasks syncing was added as was S/MIME email encryption and the following policies were added:
) from its previous version. New features included password reset which allowed users to reset a forgotten PIN lock code, message flagging which gave users the ability to mark a message so they could remember to follow up on it when they got back to their computer, Out of Office setting so users could set an “away” message from their phone, SharePoint (and UNC file share) access from links in email (file traffic was proxied though EAS), Empty deleted items to allow people to shrink their mailboxes so they didn’t exceed their mailbox size limits, fetch which allowed users to get only parts of a message and then choose later to get the rest of the message (or an attachment) later, device info which allowed users and administrators to see which phones were connected to their accounts, and AutoDiscover which (although strictly speaking isn’t part of the EAS protocol) allowed phones to automatically configure the EAS connection with just a user login and password (instead of requiring people to know the computer name of their Exchange Server). The ability to see who was invited to a meeting was also added as well as the ability to search the server for an email that was not synced to the device. The new policies introduced were:
encoding of a binary structure) to decrease the amount of data sent wirelessly, 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 at all times so battery life and data wouldn’t be consumed constantly turning on the radio and querying the server and was 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, as well as the following 30 new policies:
) and EAS, 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 so that voicemail that appeared in a user’s inbox could be handled differently, SMS Syncing (which allowed users to see their SMS messages in their email inbox and reply to them from their inbox instead of on their phone), and the following two new policies:
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.
) over EAS (a method to apply digital rights management control and encryption to email messages that are sent and received). The following is the one new policy that was added in EAS 14.1:
In December 2008 Microsoft shifted its licensing of Exchange ActiveSync from that of a protocol license, to licensing the patents of Exchange ActiveSync and providing full protocol documentation.
shows different features available from the various EAS clients.
has been posted online that helps those interested see which features are implemented in which phones.
(the desktop application) has changed its name to Windows Mobile Device Center (WMDC).
XML
Extensible Markup Language is a set of rules for encoding documents in machine-readable form. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards....
-based protocol that communicates over HTTP (or HTTPS
Https
Hypertext Transfer Protocol Secure is a combination of the Hypertext Transfer Protocol with SSL/TLS protocol to provide encrypted communication and secure identification of a network web server...
) designed for the synchronization of email, contacts, calendar, tasks and notes from a messaging server to a mobile device. The protocol also provides mobile device management
Mobile device management
Mobile Device Management software secures, monitors, manages and supports mobile devices deployed across mobile operators, service providers and enterprises...
and policy controls.
Exchange ActiveSync 1.0
The first version of Exchange ActiveSync (called AirSync at the time) was a part of Mobile Information Server (MIS) 2002. This version of EAS communicated over Web-based Distributed Authoring and Versioning (WebDAVWebDAV
Web-based Distributed Authoring and Versioning is a set of methods based on the Hypertext Transfer Protocol that facilitates collaboration between users in editing and managing documents and files stored on World Wide Web servers...
) to Exchange 2000 servers syncing Email, contacts, and calendar and allowed users to select a folder list to sync but this was only for email folders (not contacts or calendar). This initial version of EAS has the user’s device “pull” data down rather than have the server “push” new information as soon as it was available.
Exchange ActiveSync 2.0
Exchange ActiveSync (EAS) 2.0 shipped in Exchange Server 2003. This version of the protocol was developed by the Microsoft Windows Mobile team and was delivered as a binary drop (massync.dll) to the Exchange Server team. Exchange ActiveSync used WebDAV to connect to a user’s mailbox and added the ability to sync non-default calendar & contacts folders. Always Up To Date (AUTD) was implemented as a way to let a device know if there was new information for it and Short Message Service (SMSSMS
SMS is a form of text messaging communication on phones and mobile phones. The terms SMS or sms may also refer to:- Computer hardware :...
) was the technology used to deliver this information to the device. Because of the use of SMS as a notification, the configuration of an SMS gateway was required and each account needed to be configured with a user’s mobile phone number.
Exchange ActiveSync 2.1
In Exchange Server 2003 SP1 ghosting support was added to Exchange ActiveSync 2.1. Ghosting tells server what they can sync and then all is sent down but when changes are sent up, only specified fields are changed (others are not deleted). The Exchange ActiveSync protocol also moved from a Globally Unique Identifier (GUID) to 1:X short IDs for all items which reduced the amount of data sent across the wireless network.Exchange ActiveSync 2.5
Exchange ActiveSync 2.5 (Part of Exchange Server 2003 SP2) was the first version of Exchange ActiveSync to be written by the Exchange Server team. This version also introduced Direct Push (a real-time push e-mail solution which allows the server to say “I have a new item for you” and then tells the client device to do a sync (this was called a “Ping Sync”)). Global Address List (GALGlobal Address List
The Global Address List also known as Microsoft Exchange Global Address Book is a directory service within the Microsoft Exchange email system. The GAL contains information for all email users, distribution groups, and Exchange resources...
) search was added to enable people to look up other co-workers in their company directory to find their email address. The ability to remotely wipe a device was also added so administrators could remove company data from a device that was lost, stolen, or after an employee left the company. Tasks syncing was added as was S/MIME email encryption and the following policies were added:
- Minimum password length
- Timeout without user input
- Require password
- Require alphanumeric password
- Number of failed attempts
- Policy refresh interval
- Allow non-provisionable device
Exchange ActiveSync 12.0
Exchange ActiveSync (EAS) 12.0 came with Exchange Server 2007. EAS 12.0 was a complete re-write of the protocol (in managed codeManaged code
Managed code is a term coined by Microsoft to identify computer program code that requires and will only execute under the "management" of a Common Language Runtime virtual machine ....
) from its previous version. New features included password reset which allowed users to reset a forgotten PIN lock code, message flagging which gave users the ability to mark a message so they could remember to follow up on it when they got back to their computer, Out of Office setting so users could set an “away” message from their phone, SharePoint (and UNC file share) access from links in email (file traffic was proxied though EAS), Empty deleted items to allow people to shrink their mailboxes so they didn’t exceed their mailbox size limits, fetch which allowed users to get only parts of a message and then choose later to get the rest of the message (or an attachment) later, device info which allowed users and administrators to see which phones were connected to their accounts, and AutoDiscover which (although strictly speaking isn’t part of the EAS protocol) allowed phones to automatically configure the EAS connection with just a user login and password (instead of requiring people to know the computer name of their Exchange Server). The ability to see who was invited to a meeting was also added as well as the ability to search the server for an email that was not synced to the device. The new policies introduced were:
- Allow attachment download
- Maximum attachment size
- Enable password recovery
- Allow simple password
- Password expiration (Days)
- Enforce password history
- Windows file share access
- Windows SharePoint access
- Encrypt storage card
Exchange ActiveSync 12.1
Exchange ActiveSync (EAS) 12.1 came in Exchange Server 2007 SP1. This version of the protocol was one of the largest changes since version 2.5 and featured header compression (Base64Base64
Base64 is a group of similar encoding schemes that represent binary data in an ASCII string format by translating it into a radix-64 representation...
encoding of a binary structure) to decrease the amount of data sent wirelessly, 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 at all times so battery life and data wouldn’t be consumed constantly turning on the radio and querying the server and was 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, as well as the following 30 new policies:
- Disable desktop ActiveSync
- Disable removable storage
- Disable camera
- Disable SMS text messaging
- Disable Wi-Fi
- Disable Bluetooth
- Disable IrDA
- Allow internet sharing from device
- Allow desktop sharing from device
- Disable POP3/IMAP4 email
- Allow consumer email
- Allow web browser
- Allow unsigned applications
- Allow unsigned CABs
- Application allow list
- Application block list
- Require signed S/MIME messages
- Require encrypted S/MIME messages
- Require signed S/MIME algorithm
- Require encrypted S/MIME algorithm
- Allow S/MIME encrypted algorithm negotiation
- Allow S/MIME SoftCerts
- Device encryption
- Minimum number of complex characters
- Configure message formats (HTML or plain text)
- Include past email items (duration)
- Email body truncation size
- HTML email body truncation size
- Include past calendar items (duration)
- Require manual sync when roaming
Exchange ActiveSync 14.0
Exchange ActiveSync 14.0 was introduced as part of Exchange Server 2010. This new version 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, the ability to look up the availability (free/busy status) of a contact (from their calendar), a Nickname Cache which shared the names of common used contacts between Outlook Web App (OWAOutlook Web Access
Outlook Web App , originally called Outlook Web Access and before that Exchange Web Connect , is a webmail service of Microsoft Exchange Server 5.0 and later...
) and EAS, 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
Unified messaging
Unified Messaging is the integration of different electronic messaging and communications media technologies into a single interface, accessible from a variety of different devices....
) messages so that voicemail that appeared in a user’s inbox could be handled differently, SMS Syncing (which allowed users to see their SMS messages in their email inbox and reply to them from their inbox instead of on their phone), and the following two new policies:
- Allow Mobile OTA Update
- Mobile OTA Update Mode
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 photos (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 connected to their organizations, and Information Rights Management (IRMInformation Rights Management
Information Rights Management is a term that applies to a technology which protects sensitive information from unauthorised access. It is sometimes referred to as or Enterprise Digital Rights Management...
) over EAS (a method to apply digital rights management control and encryption to email messages that are sent and received). The following is the one new policy that was added in EAS 14.1:
- Allow IRM over EAS
Licensing
Beginning in the early 2000s, Exchange ActiveSync (EAS) began to be available for licensing. At the time it was a client only protocol license. Motorola was the first licensee and began with a license of the 2.1 version of EAS. Various other organizations licensed EAS over time and Microsoft eventually started licensing the server side of EAS in 2007. The protocol licensing continued until 2008.In December 2008 Microsoft shifted its licensing of Exchange ActiveSync from that of a protocol license, to licensing the patents of Exchange ActiveSync and providing full protocol documentation.
Clients
Exchange ActiveSync began being licensed in the early 2000s to mobile device manufactures. The current list of licensees is located on the Microsoft Intellectual Property licensing page. A feature comparison chartComparison of Exchange ActiveSync Clients
Notes:1 Requires free Outlook Mobile update2 Only finds email address, phone numbers, title and company3 3rd party downloadable client available for purchase for RIM BlackBerry devices...
shows different features available from the various EAS clients.
Compatibility
Exchange ActiveSync (EAS) has iterated though several versions (from 1.0 to 14.1). Because EAS is licensed as a series of patents (and not given as computer code to other companies), different clients and servers implement a subset of the entire features of the protocol and the implementations are written by each company that has obtained a license. A compatibility listComparison of Exchange ActiveSync Clients
Notes:1 Requires free Outlook Mobile update2 Only finds email address, phone numbers, title and company3 3rd party downloadable client available for purchase for RIM BlackBerry devices...
has been posted online that helps those interested see which features are implemented in which phones.
Logo Program
In April 2011, Microsoft launched the Exchange ActiveSync Logo Program, which tests third-party EAS clients in mobile email devices. Handset manufacturers that have licensed the EAS protocol from Microsoft are eligible to join the program. In order to be compliant, EAS clients must employ EAS v14.0 or later and enable the following features and management policies:- Direct Push email, contacts and calendar
- Accept, decline and tentative accept meetings
- Rich formatted email (HTML)
- Reply/forward state on email
- GAL lookup
- Autodiscover
- Allow-Block-Quarantine strings for device type and device model
- Remote wipe
- Password required
- Minimum password length
- Timeout without user input
- Number of failed attempts
Desktop ActiveSync
Desktop ActiveSync (Windows 95, 98, XP, 2000) was a desktop application designed to synchronize and set up Windows Mobile devices though a connection (USB, Wi-Fi, Bluetooth, IR) to a computer. This varies greatly from Exchange ActiveSync which is a wireless synchronization protocol. The desktop application is capable of syncing with Outlook on the desktop but not syncing wirelessly from the device to the email server (though it can configure these settings). Since the names were so similar, ActiveSyncActiveSync
ActiveSync is a mobile data synchronization technology and protocol developed by Microsoft, originally released in 1996. There are two implementations of the technology: one which synchronizes data and information with handheld devices with a specific desktop computer , and another technology,...
(the desktop application) has changed its name to Windows Mobile Device Center (WMDC).
3rd Party Servers using EAS
Microsoft license the EAS protocol and various mail-server vendors include Exchange ActiveSync support on the server side. These include- Atmail
- Axigen Mail Server http://www.axigen.com
- Kerio Connect
- MDaemon Messaging Server 12.0 (Supports version 2.5)
- Horde Groupware 4.0Horde (software)Horde is a PHP-based Web application framework.It offers applications such as the Horde IMP email client, a groupware package , a wiki and a time and task tracking software.-Horde Email Platform:...
http://www.horde.org - HotmailHotmailWindows Live Hotmail, formerly known as MSN Hotmail and commonly referred to simply as Hotmail, is a free web-based email service operated by Microsoft as part of its Windows Live group. It was founded by Sabeer Bhatia and Jack Smith and launched in July 1996 as "HoTMaiL". It was one of the first...
- Novell Data Synchronizer Mobility Pack http://www.novell.com/products/data-synchronizer/
- Open-XchangeOpen-XchangeOpen-Xchange Server is an open source project sponsored by Open-Xchange, Inc., developing collaboration software; i.e. email, calendaring, address book, etc. Product offerings based on Open-Xchange Server are marketed under the brand of Open-Xchange Server and various other names, e.g. 1&1...
(Supports version 2.5) - ZarafaZarafa (software)Zarafa is the name of an European open source collaborative software, developed in Delft, the Netherlands. The company that develops Zarafa, previously known as Connectux, is also called Zarafa. The Zarafa groupware provides email storage on the server side and brings its own Ajax-based mail client...
- ZimbraZimbraZimbra Collaboration Suite is a groupware product created by Zimbra, Inc., located in Palo Alto, California, USA. The company was purchased by Yahoo! in September 2007, and subsequently purchased by VMware on Tuesday, January 12, 2010. The software consists of both client and server components...