Linux server with M$ Outlook compatabilaty

or try this. The demo is fully functional for 5 clients.(i know you want free, but I thought it was worth taking a look)
http://www.exchange4linux.com/exchange4linux/Home

Ircpamanager
Oookay, the second like is what it is, a pay 4 product with 5 lisince trial.
The first link you gave perked my intrest more, till I saw you need "Outlook OXtender"  to make it work with outlook ... what is this "Outlook OXtender" and is that also free ?
<snip>
If you download the Outlook OXtender, then the Open-Xchange™ Server can also be accessed via MS Outlook and Palm devices.
</snip>

unfortunately it is $20 a client http://www.open-xchange.com/EN/product/outlook.html
Will keep looking, those were off the top of my head.

One plus is that you can use it with the OpenSource version.

sorry .. I'm having a hard time making sence of the sentince "One plus is that you can use it with the OpenSource version." English is my second tounge, but i'm sure there is something wrong with that sentince ?

;-)
Thanks for all the help so far

I am a lazy typist, so my sentences sometimes seem like incomplete thoughts. What I should have typed was that even though OXtender was $20.00, you can use it with the free version of  Open-Exchange.
Home many clients will you have connecting to Open-Exchange?
There is a free version(do not know how good it is!)  http://freshmeat.net/projects/dolox
No problem on the help.

There is a web based one http://www.phpgroupware.org/

This looks very interesting http://openconnector.org/ 

This is interesting:
http://www.scalix.com/products/compareeditions.html

slow1000

I didn't know about the Community Raw edition, I must have missed the announcement.

I'll have to give it a try on Centos and Debian.

Well actualy the aplication I was intending is to "mass produce" a linux NAS and mail solution to compeate with M$ server setups for SOHO.

We do allot of SBS setups for clients, but the M$ software lisinceing is such a huge expence ( specialy if you are paing in R .... R= local curnecy ) that if we (this was my bosses idea) was to set up once good NAS + PAT/firewall/sharing + POP/mail box and clone it, we could save allot of ppl allot of $$ and still increase our order flow.

I know that the TCO would eventualy even out, but to have the expences spread out over many months ( as you have with the high cost of good linux admin) instead of a miassive once off expence ( as with a M$ lisince and setup ) would suit our small clients better. A benifit for us as a buisness is that our clients would now spend the $$ on us and not on M$, and since it's a win win situation I wont feel guilty about it at all. ;-)

Thanks for all the good leads ( help with homework ;-)

Accepting ircpamanager's first answer, not cause it's the best answer but cause ircpamanager defanately answerd the question the best, be it spread over many posts.

Thanks ircpamanager

Your welcome Xorb, good luck!

Seems to me that everybody and their dog wants to build an SBS killing Linux NAS and email solution.  I have to admit it's one of those projects I've had on the backburner myself.

You might find it handy to keep an eye on this project:
http://www.thewybles.com/~charles/oser/index.html

You know why ? Cause it can be done, cause it can save some ppl money and cause there is a market for it. I think to actualy launch a project to build a almost-turnkey out the box sbs killer (I dont meen contender, I meen killer, as in "as good or better") is a excelent idea. Horaaay the revolution !! ;-)