smtp host for each user

[christian]

Its just timing and with the inclusion of Julien and Openchange which personally I think is great news,

I fully share... Openchange is a big step toward better Microsoft SBS replacement.

When it comes to the proxy I am in the explicit camp and use a script to enforce its use via a GPO.

So we are aligned... but this is also the reason why we can't understand each other. Our lines are parallel and will not cross 
- you believe in explicit proxy enforced by GPO, AKA Microsoft stuff for Microsoft domain clients
- I believe in explicit proxy too but pushed by mechanism described in RFC3040, meaning available for Windows client but not only these clients 
I can't be clearer 

I understand the need for a heterogeneous environment and your linux only argument seems as bad as the M$ monopoly?

I don't have such "Linux only" argument. 
Most of my workstations here are running Windows and I would not change for Linux because some software I need do not exist out of Windows world.
Furthermore, I even don't think Windows is always bad    It mainly suffers because this is the most widely deployed software (plus some weakness too  )
But these workstations I own are not "Windows pro" (except one) so no domain here and I frankly wonder how many SMB spend money buying pro Windows clients unless they decide, up-front, to deploy such infrastructure. No Outlook client, never using IE....
So, again, I'm not against 3.x, I just say that I don't need it.
What would 3.x bring to me that is worth the drawbacks, additional complexity, more resources requirement and, as far as I can measure from forum activity, more problems and less stability.
OK, let's be honest, I'm testing 3.x from time to time for debugging purpose, helping some forum members and I can confirm this is more complex and less stable.

However, I do not promote 2.x (neither 3.x BTW) but try to explain, when this is relevant, what are the pros & cons.

TTFN.