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Exchange ActiveSync: Frequently asked questions

Microsoft Exchange ActiveSync enables devices to synchronize your Inbox, Calendar, and other items with Microsoft Exchange Server mailboxes. This FAQ provides answers to frequently asked questions, and often includes links to content that contains additional help or more detailed explanations. This FAQ also answers questions about issues with third-party devices (such as Android and iOS devices) that synchronize with Exchange using Exchange ActiveSync.

What are the current issues with Microsoft Exchange ActiveSync and third-party devices?

Microsoft Support maintains a list of current issues that you may have when using Exchange Server 2007 and Exchange Server 2010 with third-party devices under the section labeled More information in KB 2563324  Current issues with Microsoft Exchange ActiveSync and third-party devices.

Common reasons for device issues

Not all devices support the same configuration options, and some devices may not support all features or versions of the Exchange ActiveSync protocol. Use one of the following charts to understand device capabilities.

Additionally, some devices may not have a unified update strategy and may depend upon carrier requests to create updates. Carriers then distribute those updates. Thus, updates for specific device issues may not be timely. In such situations, Microsoft may direct customers to contact their mobile carriers for assistance.

Note:  Exchange ActiveSync Licensees provide the Exchange ActiveSync software that is used on the third-party devices. Microsoft does not write the Exchange ActiveSync code for the licensees’ devices or services. Microsoft licenses patents, which are Microsoft Intellectual Property, to Exchange ActiveSync licensees. Microsoft also provides public access to the Exchange ActiveSync protocol documentation.

How can I troubleshoot problems with Exchange ActiveSync?

Start with the following resources. If one of these does not address your specific issue, try searching Microsoft Support.

Knowledge Base articles


See also

What types of mobile devices can be used together with Exchange ActiveSync?

Devices listed on the Exchange ActiveSync Logo program page meet the requirements of the Exchange ActiveSync (EAS) Logo program. These devices provide critical EAS end user features and offer superior security and management.

There are other devices that are EAS-enabled, but that either support different configuration options, or lack support for some of the features or versions of the Exchange ActiveSync protocol.

Use one of the following charts to look up the capabilities of some of the more common implementations of EAS.

See also

How can I correctly calculate how many devices my Exchange organization can support?

Each mobile device manufacturer and Operating System version is different.  Reviewing how devices perform in test environments can yield varying results, and device manufacturers do not submit performance information to Microsoft. Following are general guidelines and tools.

See Also

You can use the following tools for reporting and evaluating device synchronization behavior.

Why don't the Windows Phone 7 devices in my organization work as expected with ActiveSync?

Because of changes in the new Windows Phone 7 application platform that were made to provide greater control of applications distributed to the phone and standardization of the underlying hardware platform, some Exchange ActiveSync features and policies are less applicable or apply differently to Windows Phone 7.

Issues for Exchange Server 2010

If you have Windows Phone 7 mobile phones in your organization, these phones will experience synchronization problems if certain Exchange ActiveSync mailbox policy properties are configured in Exchange Server 2010. To allow Windows Phone 7 mobile phones to synchronize with an Exchange Server 2010 mailbox, either set the AllowNonProvisionableDevices property to TRUE or only configure the following Exchange ActiveSync mailbox policy properties:

  • AllowSimplePassword
  • BlockInternetSharing
  • BlockRemoteDesktop
  • DeviceWipeThreshold
  • DisableDesktopSync
  • DisableIrDA
  • DisableRemovableStorage
  • IdleTimeoutFrequencyValue
  • MinPasswordLength
  • PasswordExpiration
  • PasswordHistory
  • PasswordRequired


Issues for Exchange Server 2003

Currently, Windows Phone 7 devices cannot resolve addresses within a Global Address List (GAL) on an Exchange Server 2003 server. For more information, see KB 2463128: You cannot search the Global Address List with Windows Phone 7 when connecting to Exchange Server 2003.

See also

What Exchange ActiveSync policies does Windows Phone 7 support?

Windows Phone 7 supports the following Exchange ActiveSync (EAS) policies for the following versions of Exchange Server.

EAS policyExchange Server 2003Exchange Server 2007Exchange Server 2010
DeviceWipeThreshold SupportedSupported
IdleTimeoutFrequencyType SupportedSupported
MinPasswordLength SupportedSupported
PasswordExpiration SupportedSupported
PasswordHistory SupportedSupported
PasswordRequired SupportedSupported

The following EAS policy settings always return TRUE for Windows Phone 7 devices.

  • AuthenticationReset
  • BlockInternetSharing
  • BlockRemoteDesktop
  • DisableDesktopSync
  • DisableIrDA
  • DisableRemovableStorage*

All other EAS policy settings always return FALSE for Windows Phone 7 devices. For explanations why the previous list of policies always return TRUE and why certain policies always return FALSE, refer to the article labeled "Windows Phone 7 and Exchange Server" on the Windows Phone 7 Guides for IT Professionals download site.

*For more details on storage support in Windows 7, download the article entitled “Windows Phone 7 security and management” from Windows Phone 7 Guides for IT Professionals.

See also

What functionality does Exchange ActiveSync provide for the Windows Phone 7 People Hub and Outlook Mobile?

People Hub

The Windows Phone 7 People Hub presents contact information provided by Exchange ActiveSync (EAS). Because EAS enables users to configure multiple EAS accounts on a Windows Phone 7 device, People Hub can present contact information for multiple EAS accounts.

Outlook Mobile

Outlook Mobile on Windows Phone 7 uses EAS to provide:

  • Smart filtering (enables users to pivot to unread, high-priority, or flagged messages)
  • Smart search (enables users to type a few search characters and see instant results)
  • Multiple message action processing (enables users to add a flag, delete, mark as unread, or move multiple messages)
  • Tight calendar-email integration (enables users, for example, to send a one-tap prewritten response to meeting invitations when in calendar view)

What is Direct Push?

Direct push is a feature that maintains an open connection between the mobile device and the server. When direct push is enabled, new mail items are automatically pushed from the Exchange server to the mobile device without requiring SMS notification messages. Direct push has been built in to Exchange Server since Exchange Server 2003 Service Pack 2.

Devices that support direct push issue a long-lived HTTPS request to the server running Microsoft Exchange. The Exchange server monitors activity on the user's mailbox and sends a response to the device if there are any changes, such as new or changed e-mail messages or calendar or contact items. If changes occur within the lifespan of the HTTPS request, the Exchange server issues a response to the device that states that changes have occurred and the device should initiate synchronization with the Exchange server. The device then issues this request to the server. When synchronization is complete, a new long-lived HTTPS request is generated to start the process again. This guarantees that e-mail, calendar, contact, and task items are delivered quickly to the mobile phone, and the device is always synchronized with the Exchange server.

See also

Understanding Direct Push

Can Exchange ActiveSync be used in a single server environment where forms-based authentication is enabled?

Yes. However, when you use Exchange ActiveSync to access an Exchange Server 2003 computer that has forms-based authentication enabled, you may receive a server synchronization error. For more information about the Exchange ActiveSync error that occurs when forms-based authentication is enabled, see Exchange ActiveSync and Outlook Mobile Access errors occur when SSL or forms-based authentication is required for Exchange Server 2003.

What types of data can be synchronized by using Exchange ActiveSync?

Exchange ActiveSync enables you to synchronize your e-mail messages, calendar, and contacts lists in your Exchange Server 2003 mailbox with a Microsoft Windows Mobile powered device.

Can I synchronize my e-mail messages, calendar, and contact information with my desktop by using Exchange ActiveSync?

Exchange ActiveSync is a server-side technology that lets Exchange ActiveSync-enabled devices synchronize mailbox items through a wireless connection without using a desktop computer, cradle, and desktop synchronization software.

You can also synchronize your mobile device with the Exchange server by using the desktop pass-through option that is present in all Windows Mobile powered devices. Desktop pass-through lets your cradled device use the desktop computer's Internet connection to connect to Exchange ActiveSync. You can then perform tasks such as browsing the Internet or downloading IMAP4 or Post Office Protocol version 3 (POP3) e-mail messages.

After Exchange ActiveSync creates a connection and a partnership between the device and the desktop computer, by default desktop pass-through is enabled, even if the desktop is locked or protected by using a password.

Can I synchronize other folders in addition to the Inbox?

After you synchronize your Inbox for the first time, you can select other folders in your mailbox for synchronization. You can configure synchronization of your Inbox and other folders by using Exchange ActiveSync on your desktop or mobile device.

Can I schedule synchronization?

Synchronization can be scheduled. Windows Mobile devices provide many scheduling options. You can configure different synchronization schedules whether or not you are connected to your computer. By using Exchange ActiveSync, you can schedule synchronization of your device on two separate schedules—peak or off-peak times. Custom scheduled synchronization gives you control of when and how frequently you update your data (Figure 1). You can use the peak times schedule to synchronize during working hours or other times that you experience high mail volumes. Use the off-peak schedule to synchronize during times when you experience low mail volumes.

Figure 1   Examples of custom scheduling synchronization

Pocket PC Phone Edition devices or smartphones that are running Windows Mobile 2003, Windows Mobile 2003 Second Edition, and Windows Mobile 5 can receive up-to-date notifications. Up-to-date notifications generated by Exchange Server 2003 initiate Exchange ActiveSync synchronization between a user's device and their Exchange mailbox.

In ActiveSync, if I clear the check box for a folder that has been synchronized to the mobile-based device, does that action delete the items from the Exchange server?

No. When you disable synchronization for any folder on your mobile device, only the data that is stored on the device is deleted. Data stored on the Exchange Server computer remains intact.

If you disable the synchronization of a folder on your mobile device, ActiveSync prompts you with the following message:

All e-mail synchronized to your device using ActiveSync must be removed to proceed. Select OK to continue.

You can then confirm that you want to disable synchronization of the folder.

When I synchronize my e-mail, can I synchronize only the e-mail header information?

If you want to conserve storage space on your device, you can synchronize only the e-mail header information. Exchange ActiveSync enables you to modify several Inbox synchronization settings. For more information about how to configure your Inbox synchronization settings, see the Exchange ActiveSync Help.

If I only want to synchronize header information the first time synchronization occurs, can I change this option later to synchronize the message body for existing and new messages?

Yes. After you synchronize the header information the first time, you can clear the Inbox option, synchronize your device, and then select Inbox again. This deletes existing messages on your device. When you synchronize again, messages will include the message body. For more information about how to configure synchronization settings, see the Exchange ActiveSync Help.

How can I control which users have access to Exchange ActiveSync?

By default, all users are enabled for Exchange ActiveSync. An Exchange Server administrator can globally disable Exchange ActiveSync for all users in Exchange System Manager by using the Mobile Settings option under Global Settings. You can also enable or disable individual users by using Active Directory Users and Computers.

Does Exchange ActiveSync require SSL authentication?

It depends on the device. Windows Mobile 2002 powered devices connect over Secure Sockets Layer (SSL). Windows Mobile 2003 powered devices do not require SSL. However, it is strongly recommended that you use SSL to protect your data and credentials. To enable SSL authentication on Windows Mobile 2003 powered devices, in the ActiveSync Server Synchronization settings, select the This server uses an SSL connection option.

How do I add a root certificate to a smartphone or Pocket PC?

Windows Mobile powered smartphones use the CryptoAPI certificate store to securely store root certificates. For more information about how to add a root certificate, see How to add root certificates to Windows Mobile 2003 Smartphone and to Windows Mobile 2002 Smartphone. For more information about how to download a sample application, see the Microsoft Download Center Web site.

How can I configure Exchange ActiveSync to support multiple SMTP domains?

Exchange ActiveSync locates a user's mailbox by using the primary Simple Mail Transfer Protocol (SMTP) address. However, if users have a different SMTP domain in their e-mail address, they cannot synchronize their mobile device with Exchange Server 2003. To address this issue, you must add a registry key to force Exchange ActiveSync to locate the user's mailbox by using a secondary SMTP addresses. For more information about how to configure Exchange ActiveSync to locate users' secondary e-mail addresses, see You receive an HTTP_500 error message when you synchronize your mobile device with Microsoft Exchange Server 2003.

Caution: Incorrectly editing the registry can cause serious problems that may require you to reinstall your operating system. Problems resulting from editing the registry incorrectly may not be able to be resolved. Before editing the registry, back up any valuable data.

Why are attachments not synchronized to the device even though I configured the device to synchronize attachments?

Exchange ActiveSync uses the X-MS-ENUMATTS verb to retrieve attachments from the Exchange server. If UrlScan is configured on the Exchange server, make sure that the X-MS-ENUMATTS verb is allowed on the Exchange server. For more information about issues that are related to the UrlScan security tool, see Microsoft Knowledge Base article 823175, Fine-tuning and known issues when you use the Urlscan utility in an Exchange 2003 environment.

Why are my mailbox items not being downloaded to the device?

Exchange ActiveSync uses the If header when it retrieves mailbox items from the Exchange server. If UrlScan is configured on the Exchange server, make sure that it is not included under [DenyHeaders]. For more information about issues that are related to the UrlScan security tool, see Microsoft Knowledge Base article 823175, Fine-tuning and known issues when you use the UrlScan utility in an Exchange 2003 environment.

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