Kolab, exim and multiple accounts per user

[schönfeld / in-medias-res]

Hi there,

in our current setup we run a mailserver based on Debian, exim as MTA 
with several spam filtering mechanisms. Now we want to migrate to a 
solution providing us with groupware functionality like calendars, todo 
lists, network-wide-addressbooks etc. On my first sight i thought Kolab 
could be _the_ solution we want, but there are a few points i'm stuck
on and need questions before i i evaluate it, so i hope to get answeres 
here :-)

So here we go:
1. Does Kolab support multiple E-Mail Acounts per User (say: Our users 
have several e-mail addresses (e.g. the ordinary standard account, a 
support account, a group account, ... ) which they write from and 
receive mails on. They are seperated from each other and that is 
wanted.) That is done by several e-mail accounts and is working exactly 
as it is wanted. Now does Kolab support such a scenario? Is it possible 
to have several e-mail accounts (maybe even _with_ its own cals, etc.) 
but don't let them have their own groupware account (which doesn't make 
sense in my opinion?)

2. Is their any possibility to use exim instead of postfix? Cause we are 
working with exim on every server we ever installed and administrated. 
Therefore we have gathered a lot of knowledge about exim and therefore 
would like to avoid changing things to postfix which we do not know much 
about. If someone knows about this topic: please let me know.

Thanks in advance :))

Patrick
IT Manager
IN MEDIAS RES