This software together with Funambol looks like an interesting alternative to Zimbra/Zarafa/Kerio/etc.
Though it has not Outlook look&feel there is a BBS look look&feel :)
I have found it pretty stable when installed from standard Debian Lenny repository, though more recent version on developer's website has several glithes like hanging and eating too much CPU when trying to see mail queue, etc. Hope they will fix such issues for the next Debian release.
Anyway, for those who dicided to try here is a script which let easilly create new users. Also it is an example of sending commands to the citserver using citadel app protocol. Before using please edit it and type in your administrator username and password at the head of file.
1. Install Citadel on Debian Lenny:
2. Restart both Citadel services:
3. Create a new user (in database auth mode):
/utils/citadel.pl create_user newuser1 password1
4. Uninstall Citadel completelly (all data directories are removed too, which can be usefull for reinstall with configuration):
(c) Alexander Prokopyev 2009 (TS e-Notary)