Interesting question because I'm thinking about a groupware tool since a couple of weeks.
I'm thinking:
TWIG:
Seems easy to install on an E-Smith-System but is only usable with an online connection.
HPOpenMail:
- Up to 50 users you get a free license from HP
- Accessable from Nodes or Outlook Clients, so I understand its usable also offline
I would not try to install it on my E-Smith Server, because it uses sendmail not qmail.
StarOffice 5.2:
I read an article about the new StarOffice 5.2 Version which includes a Server Daemon for Linux or WinNT Server
The syncronisation is also possible with emails for clients without an online connection
Michael Jung