What is the Exchange ActiveSync Up-to-date feature and how does it work?

One of the new features in Exchange 2003 is Exchange ActiveSync.  Exchange ActiveSync allows you to synchronize your Windows Mobile 2003 Device with your Exchange mailbox over a wireless network without having to cradle the device.  The Up-to-date (UTD) feature notifies the device if there is a new item in the Exchange mailbox and the device will automatically initiate a synchronization with you mailbox.  This feature gives the user an always on and always current feeling.  The other benefits of this feature are better device resource utilization, a more consistent user experience when compared to device expectancies and this operation is done in the background without the device turning itself on.

What happens on the Device:

The UTD notification is an SMS message that is processed by the device at the TCP/IP level, so the user will never see the SMS message in their SMS Inbox.  It is a control message with a Globally Unique Identifier (GUID) in it.  The mobile client will match this GUID with the most current one that it has.  If they match, the device will schedule a synchronization to occur within 3 minutes.  The reason for the 3 minute wait is to handle the case when the device has been offline and the operator has queued up messages to be sent, when the device comes back on line all notifications are sent to the device.  We want the device to synchronize only once for these changes. 

How the message gets to the device:

The UTD notification will leave the Exchange environment as an SMTP message.  It is destine for a Mobile Operators SMTP front-end server.  This is not always available, especially in Europe and Asia.  Make sure to verify that the Mobile Operator being used does support inbound SMTP.  Once the operator receives this message, they will convert the SMTP packet into an SMS message and forward it on the the device.

How the Exchange Server 2003 processes the UTD notification:

Exchange monitors the mailbox with an Event Sink that runs in the Exchange Store.  There is an Event Registration Item in all folders that have been provisioned for Synchronization.  When a new item arrives in the folder, the Event Sink is called and creates a message containing all of the user information needed to get the message to the device.  It is then passed to the Exchange transport for verification and formatting.  A few things happen at this point.  1) The device has an expiry date assigned to it, which is checked.  If it is in the past, the notification is not sent. This expiry is set when the device synchronizes with the mailbox.  2)  The GUID in the message (mentioned above) is also verified, if it has already been sent, then the new notification will be dropped.  There is a time limit of 15 minutes for this in case the new notification is not received by the device.  3) the GUID is compressed and encoded before sending.  Once this has been accomplished, the notification is addressed to the devices SMTP address and send through the regular messaging transport.

- Steve Mattox

Comments (23)
  1. Chris Kinsman says:

    Cool! Now if Exchange ActiveSync didn’t return a server error so frequently and fail to synchronize…

  2. Benjamin Mateos says:

    Thanks! Really interesting info.

    Keep up the good job!.



  3. Karan says:

    This has been a feature I was waiting for since the MMIS days. The only drawback about this implementation is that the user gets cahrged for an SMS (unlike RIM’s control messages). For a heavy mail user this can ammount to a hefty charge on their monthly bill (on top of the data charges to retrieve the actual email).

  4. adam says:

    Okay, so does anyone know T-Mobile’s SMTP front-end server to convert my messages to SMS?

  5. lonnie says:

    Timely info. Keeping blogging this great info. Thx!

  6. George says:

    So, if someone intercepts the SMS they will be able to retrieve the target’s e-mail. And since the notification uses SMTP – welcome to the new era of spam.

    Thank you for the great new opportunities, M$!:)

  7. What?? says:

    Can’t even respond to that last comment. Re-read the article please!

  8. Neil says:

    The way to send SMS messages to your T-Mobile device via e-mail is number@voicestream.net, where number is 4255551212 (area code + seven digits).

  9. Nirav says:


    Is this strictly for inbox mail notification and syncing of email or can I sync files , databases etc via activesync using this?

    Lets say I’m using the PocketRSS client and getting the latest RSS feed updates when I put my device in the crade. Could I possibly trigger a remote active sync connection when the exchange server notifies my device of a new inbox message and pull down file updates or rss feed updates?

  10. Steve Mattox says:

    When Exchange ActiveSync Up-to-date is set up, ActiveSync will kick off a sync when a new item arrives in your mailbox. The device can also sync remotely with your PC if configured correctly and you can VPN to your PC from the PPC. So it is likely that if this application syncs with your PPC through Desktop ActiveSync, that it could possibly sync remotely when a new mail arrived in your mailbox. If the application has any UI that needs to be manipulated, the sync will probably not work. Try it, let us know if it works

  11. Owen Stevens says:

    We are pilot testing an Audiovox PPC-5050 with Exchnage 2003 published through ISA 2000. I can initiate ActiveSync from the device, and it works fine. However, I am receiving up-t0-date notification. I have gone through the step by step setup based on Microsoft deployment guide. What, I don’t understand is how exchnage knows about my device, and how is it going to send SMS to my device as a wake up call for ActiveSync. Where should I eneter that information?

  12. Owen Stevens says:

    …However, I am receiving up-t0-date notification…

    I meant : I am NOT receiving up-to-date notifications

  13. Steve Mattox says:

    Owen, here are a couple things to check for on the device. Are you running Windows Mobile 2003 on the device? If not, you need to be. If so, is there the option called "When new items arrive" on the schedule page? If yes, then select this option. You will then need to enter the device’s SMTP address. If you do not see this Scheduling Option, then the device does not know that the service is available to it. This usually means that the first request that the device made which asks for what Options are available is getting blocked. It could be being blocked by the ISA server. Either use SSL from the device or configure the ISA server to allow the OPTIONS verb.

  14. Owen Stevens says:


    Is it something under ActiveSync->Mobile Schedule?

  15. Steve Mattox says:

    Yes, ActiveSync->Tools->Options->Mobile Schedule.

  16. Owen Stevens says:


    Thanks a lot it is working now. It appeared to be that, we added the OPTIONS registery key but forgot to set it to 1. That was it.

    Thanks again

  17. H. Yahi says:


    How can i synchronise The Public folder op exchange 2003 with IPAQ Pocket PC.

    I want the synchronisation to occur with the server not with local client outlook.

    Kind regards

  18. Raj Kaimal says:


    I am testing theh up-to-date function on the Smartphone 2003. Everything works fine but it takes around 13 minutes (after it arrives in my outlook inbox) to get notified on the smartphone that I have new mail. The provider is AT&T. I don’t think it is their problem because if I send an sms message to the smartphone using smtp (xxxxxxxxxx@mobile.att.net) I get it immediately on the smartphone.

    Is the delay of 3 minutes that you metioned set somewhere on the smartphone? Thanks for your time.

  19. Steve Mattox says:

    Raj, AT&T blocks all incoming mail as if it were spam if it does not have an address in the FROM field. Our notifications do not have a FROM address, therefore AT&T will drop our messages. Take a look at

    http://support.microsoft.com/default.aspx?scid=kb;en-us;833745&Product=exch2003 for the details

  20. Dave says:


    How does Exchange ActiveSync handle attachments? Are they converted with the typical file filters that a desktop sync would have or are they passed straight through to the device? For example, if I have an MS Word document in an email, will it sync as is or will it get converted to a Pocket Word attachment (.pwd).



  21. Yan (Steve Mattox's friend) says:

    Exchange ActiveSync does not convert attachments at all. The attachment that is found on the server is that which will be retrieved by the device; therefore a word document will be downloaded as is (not as *.pwd).

  22. Anonymous says:

    If you’re not familiar with it, it basically sends periodic notifications of new mail to your Windows Mobile device; when the device receives the AUTD message, it wakes up and pulls new messages from your Exchange server…. There’s a way to control the batching behavior, but it’s not obvious: you have to create a new REG_DWORD named BatchingTimer under the SoftwareMicrosoftExchangeOMA key (if OMA doesn’t exist, create it first).

  23. Anonymous says:

    I was just on Microsoft BetaPlace downloading the Microsoft Device Emulator 1.0 Community Preview to test Windows Mobile 5.0 with Exchange ActiveSync and the download timed-out at 98%. 2% remaining? Such a tease… I then tried accessing http://beta.microsoft.com

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