I would like to set up a groupware server on my Hardy Server Platform with clients on Vista, Windows XP, and other Ubuntu PCs, and ideally the ability to sync with Pocket PCs (WinMobile 2003 2nd edition) would be desirable as well. The Windows PC clients don't have to be Outlook, but would be nice. There will be approximately 5 users.
I'm looking to support calendaring, notes, tasks (toDo's), and e-mail. The data needs to stay "on the server" so that a client from any of the computers will see the same information.
There seems to be a quite a few choices, any suggestions on which ones are easiest to operate/maintain/setup?