Earlier this week, Microsoft took the wraps off the Messaging and Security Feature Pack for Windows Mobile 5.0 and Exchange Server 2003 Service Pack 2.
At the time of the announcement, this system was touted as a push email system. However, it turns out that whether or not this is true depends on how one defines push email.
In push email, as soon as an incoming email arrives on the server, it is pushed out to the device, and the user is immediately notified of it.
This is the system used by RIM’s BlackBerry line of wireless handhelds, and what has made them so successful.
However, this isn’t exactly how Microsoft’s upcoming system works.
According to Sami Khoury in the Microsoft Exchange Team Blog, the device periodically sends an HTTP request to the server, which asks Exchange to report any changes that occur in the mailbox of the requesting user within a specified time limit.
If no new emails arrive, the server will send an empty response message at the end of specified time. The device will then send another HTTP request to the server, starting the cycle all over again.
On the other hand, if a new message is received by the server, it will immediately send a response back, telling the device it should start a wireless ActiveSync. This will let the device connect to the server and download the changes. After this is done, a new HTTP request goes to the server to wait for the next message.
This system can handle more than just email; it can also look for changes in the user’s calendar, contacts, and Tasks, and during the ActiveSync session only the appropriate categories will be updated.
The developers of this system don’t believe it will be an unbearable strain on the battery of the handheld or smartphone. GPRS radios do not consume power unless they are actively transmitting, and most of the time the device will just be waiting for a response from the Exchange server.
While the email system Microsoft has developed doesn’t exactly match the dictionary definition of push email, it’s very close.