Microsoft has added to its mobile offering.

Microsoft CEO Steve Ballmer explained that the Messaging and Security Features Pack for Windows Mobile 5.0 would combine with features coming in Service Pack 2 (SP2) for Exchange 2003 to address requests by business customers for a faster, more direct messaging experience.

The implications for RIM, and indeed all the other push email vendors currently challenging the dominance of the Canadian vendor’s BlackBerry service, are evident.

Of course, Windows Mobile is not the market leader in mobile OSes, ranking well behind Symbian in the smart phone market, but tighter integration with Exchange may well encourage more handset manufacturers to base products on the OS. Exchange is responsible for between 30% and 40% of the email server market and is particularly strong in Europe.

Microsoft has already shown how concerned it is for Exchange to hold sway in mobile email. Earlier this year it licensed the ActiveSync technology by which it syncs up with remote/mobile clients to Symbian, the organization responsible for furthering the eponymous mobile OS that rivals Windows Mobile.

However, if manufacturers can be convinced that a Windows client talking to an Exchange Server will offer greater functionality, and corporate users start showing a preference for these devices, it could start to tip the scales in Microsoft’s favor.

Steve Maynard, senior marketing manager in Europe for push email developer Visto, which has just cut a global deal with Vodafone, said the Microsoft announcement sounded like it was working on a direct client-server architecture, whereas we put a lot of the power work into a Network Operating Center, an approach which clearly appeals to operators, as they can run the NOC and charge accordingly.

If a company can deliver push email off the Exchange Server it is already running (or even better if it does so over, say, a VoIP connection), there is the potential for cutting operators out of a good part of the loop, restricting their function to that of providers of bit-pipes.