BlackBerrys may be the most established smartphones in the corporate world, but Global Crossing is one corporation that can't wait to get rid of them.

The telecommunications firm, which provides networking services such as VPN, video conferencing and VoIP in 60 countries, is on the hunt to improve unified communications for its 5,000 worldwide employees.

With this goal in mind, Global Crossing is taking the leap to Exchange 2010 from Exchange 2007 for its e-mail archiving capabilities, connection to cheaper storage, and as a replacement for its current voicemail system.

But the Exchange 2010 migration is also a chance for Global Crossing to wean itself off BlackBerry smartphones and onto Windows Mobile 6.5 phones, thereby eliminating the fees required to make BlackBerrys available to employees.

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"RIM requires that you pay for a license for the BlackBerry servers," says Steven Schafer, Director of Network Services at Global Crossing. "You pay a license for every BlackBerry user that you have connected, and then you also pay for support and maintenance for the servers and users."

But Is WinMo 6.5 Good Enough?

Despite the cost savings Global Crossing could reap by ditching BlackBerry servers and licenses, Windows Mobile 6.5 has faced some harsh criticism since it launched a month ago. It was mostly panned by critics and, based on recent customer satisfaction studies, it has fallen way behind the iPhone and BlackBerry in the smartphone race.

[ For complete coverage on Microsoft's new Windows 7 operating system -- including hands-on reviews, video tutorials and advice on enterprise rollouts -- see CIO.com's Windows 7 Bible. ]

Most of the gripes about Windows Mobile 6.5 are that it is a stopgap before the arrival of Windows Mobile 7, with underwhelming interface and touchscreen features. But even though WinMo 6.5 is not being hailed as a great mobile OS for consumers, critics admit that it's a solid enterprise mobile OS given how well it integrates with Exchange.

Schafer is counting on such a smooth integration with Exchange 2010 and Office Communications Server. It's what sets WinMo 6.5 apart, despite its lackluster reviews, he says, adding that he expects more enhancements with the arrival of Windows Mobile 7 in the second half of next year.

Also, unlike any other mobile devices, Schafer says, WinMo 6.5 phones are the only ones that have the Outlook Mobile client that uses the new features in Outlook 2010 such as Conversation View of e-mails and having audio and transcriptions of voicemails delivered to inboxes.