[tacticalogic]

So your actual requirement is to not have that bottleneck, not to have Microsoft's specific solution to that bottleneck as caused by Exchange. It's hard to write neutral requirements when you're vested in one specific technology.

If it didn't cost anything to tear it all out and start over, you could.

[antiRepublicrat]

Let's quit the nitpicking and go back to the original question -- is Mac viable for this? In the case of a migration, every company has to look at its specific circumstances. Let's say you're making your five-year budget and its time for new hardware. You can stay with Windows and count the license and personnel costs for that time. Or you can go Mac and incur a large migration cost. The math is different each time. But say your migration cost is $400,000. You make that up in one mid-level support position. The license savings are gravy. Sometimes it won't play out that way.

But if you're setting up from scratch I can't see how anybody would go with Windows if all options were researched.