I just installed Kolab on my desktop machine, just to play around with it, and I must say I'm impressed. This is the most integrated groupware-like suite I've ever worked with.
Based on existing open source solutions like
- Cyrus Sasl
- Cyrus IMAP
and others, you get a completely integrated mailserver, userbase, calendars,... with a nice webinterface for administration purposes.
I installed Horde as user frontend, which took some time, but now it's working almost well. Using Horde the user gets a well-integrated web interface to his email, calendars, address books, Sieve mail filters, notes and tasks etc.
This is definately something we should look into at VTK. When using Horde as user interface, we could even allow our users to access their Eduserv email from the same interface etc, which would be really nice. The implementation could easily be done in a multiple steps: first get all email stuff working, then addressbooks, then calendars,...
I wonder whether it could be possible to extend the "standard" Kolab "User" LDAP object so it can also be used for Samba3 LDAP authentication? If that'd be possible, this is definately the application to use on our new server :-)
Screenshots might follow later ;-)