The so-called 'Direct Push' technology eliminates the need for Microsoft mail servers to notify remote users of new e-mail via text messages. New calendar appointments, contacts and task notifications can also be automatically sent out.
The feature is aimed squarely at allowing the software behemoth to compete more evenly with handheld e-mail giant Research in Motion, which sells the popular BlackBerry device line.
Another significant new feature included in the update is support for Sender ID, an e-mail authentication protocol which Microsoft is backing as a solution to spam against rivals like DomainKeys, which is being pushed by companies like Yahoo and Cisco.
Sender ID verifies the Internet address of the server which sent an e-mail against the known IP address of the domain which it claimed to come from. This helps to evade a technique known as 'spoofing' in which spammers send e-mail from fake address to avoid being caught.
Also included is the ability to wipe data from remote devices using the Windows Mobile operating system, which is designed to integrate closely with Exchange 2003. The technique is aimed at stopping sensitive data being retrieved from stolen devices. A similar wipe can also be automatically initiated if the wrong password is given too many times on a device.
A whole host of additional minor updates are included, for example better data compression techniques, the ability to support the S/MIME standard for encryption on hand-held devices, improved anti-spam filtering and an increase in the size of mailbox storage limits to 75Gb.
Apart from the new features, SP2 for Exchange 2003 fixes a huge list of bugs found in previous incarnations of the software. One serious example is a case where e-mail addresses found in the blind carbon copy field of a sent e-mail (which are normally hidden from recipients of an e-mail) could be disclosed if the e-mail was forwarded as an embedded attachment.
The update can be downloaded from Microsoft's Web site, and installed over the top of SP1 and the previously released technology preview of SP2. To take full advantage of the new mobile device features, users will need to be running Windows Mobile 5.0 and the additional Messaging and Security Feature pack.