"exchange" Question

Hello Folks, who's IQ seems to be better than mine at the moment.

i have a burning question: what kind ofsoftware do i need to create a GOOD Calobaration server (in M$ Win called M$ Exchange) that does not rewrite my Root permissions.
i tried Kolab and Zimba (opensource) but they rewrite the permissions of my root and the users.
i tried Open-xchange , but this perticular colaboration program only works when i do run from the boot, this means opensuse can not be started.

i read some articles about open-xchange that it was sort of "build-in" into opensuse (for what i can remember readed) version 10.2

is there in openSuse a option to create this, if yes, can i somewhere fins a good howto to do it myself?

i had a win2k3 server with M$ exchange but the support of ms was terrible, i desided after reading lot of articles to switch over to opensuse 10.3
and i must say, i am elited, what is suse-linux changed since 8.2. the suse 8.2 is still running at my place as a samba-backup server, it runs and runs and runs for almost 5 years now without any problems, i installed lot of extra's and i never ever had to reboot it.
my suse 8.3 - pII 400Mhz - runs from the first moment i installed suse 8.2.

but opensuse 10.3.. man what a job, i have now the 3rd reinstall becouse of this colaboration-server software that does the rewrite root-permissions...
please can any one of you give me a very good advice so that my opensuse runs as stabile like my suse 8.2 samba-server?

thanks in advance
Richard aka Klinky