This story isn't a reprint from 1991. Or from 1994. It's not even a reprint from 2010. Microsoft has once again publicly called out the dwindling market share of IBM Lotus Notes, rekindling a decades-old feud ahead of Lotusphere 2011. Is The VAR Guy surprised? Not really. But this time, Microsoft isn't teasing IBM by offering free training or promoting its channel partners; rather, it's going in with both guns blazing, armed with market share statistics and highlighting enterprises that have made the switch to Microsoft Exchange from Lotus Notes. Here's the scoop:

In a post on the Microsoft Unified Communications Team Blog titled, "Don't Be the Last Company on Notes," Microsoft Senior Director of Exchange Product Management Julia White cites an internal research study from last year that confirms Exchange's market dominance in the large enterprise to the tune of 73 percent share. In second place with 7 percent, she says, is Lotus Notes.

Of course, when Microsoft reports its own statistics, The VAR Guy's hype alarm goes off. And there is the caveat that Microsoft's numbers only include enterprises with more than 500 seats -- which ignores the smaller enterprises that are the bread-and-butter of cloud service providers like Google Apps or even BlueTie. All the same, White claims that more than 20 million Lotus Notes messages have been migrated to Microsoft Exchange over the last five years.

Every day this week until Lotusphere - which is taking place Jan. 30-Feb. 3 in Orlando - White plans to highlight enterprises that made that switch, and praise the Microsoft partners who helped migrate Lotus users to the Exchange platform. It's also worth noting that Microsoft hit that 73 percent market share in part due to the efforts of hosted Microsoft Exchange providers such as Intermedia and Apptix -- it hasn't all been from direct sales and BPOS.

But between the buzz around the launch of Microsoft Office 365, and with upstarts like Google Apps going after the Lotus installed base as well, The VAR Guy wonders whether White has a point when she says 2011 marks the end of the line for IBM Lotus Notes.

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