A new Yankee Group survey of IT executives shows that 23% respondents intend to migrate off of Exchange to Linux-based mail servers in the next 12-18 months. Of the respondents, 65% of them currently run Exchange.

I’m extremely skeptical about this report. I honestly doubt that even half of that 23% will end up migrating. I went through a similar process in my last job. I launched our original e-mail platform on Linux using sendmail (which I soon replaced with Qmail) and a basic POP3 server. Within the first year that solution simply wasn’t robust enough because users needed to share calendar, task, and other collaboration data. I did not want to go to Exchange Server.

Since I wanted to avoid Exchange – mostly because of cost – I explored and tested a bunch of different Linux solutions, including HP OpenMail (that was a disaster). Eventually, the search reached the point of diminishing returns, so I threw my arms in the air and bought Exchange. I was a glad I did. It solved the problem, was easy to backup, and easy to manage.

Of course, that was Exchange 5.5. I’ve heard horror stories from colleagues about the migration to Exchange 2000 and Exchange 2003. Now, Exchange 2007 is here and it has some extremely hefty resource requirments, including the fact that it has to be installed on a 64-bit OS.

I have no doubt that the migration issues with recent versions of Exchange and the big Exchange 2007 resource hurdle is what has many IT managers rethinking Exchange and seriously considering a switch to Linux. Still, I doubt many of them (certainly not 1/4 of them) will make the switch once they do a full evaluation of what they would have to give up in moving away from Exchange.

That being said, there are now more and better Exchange alternatives in Linux than there were when I was going through this process in 2000. For example, if Scalix was an option at the time, then I would have seriously considered it. Nevertheless, even with Scalix you have to give up some things in terms of manageability and some features (e.g. Windows Mobile integration). That’s why I think the number of Exchange defectors will still be far less than 23%.

For more information on the Yankee Group survey, check out Mary Jo Foley’s report. For more on Scalix, take a look at this post from George Ou.