Hi Darren,
If I was setting things up from scratch these days, I'd go with Mambo. There's also a hint of
moodle integration, but I don't know how far this has got.
There's a very nice try before you 'buy' facility over at
opensourcecms.comI tried e-groupware for a while, but wasn't too impressed - far too many quirky ways of doing even relatively simple things like imap.
We use
squirrelmail for our web-based email, and there's a file management plug-in which allows users access to their home directories from, erm, home - I'm not sure how secure this is. There are also plugins for calendars and contacts.
I wonder how much of this could be achieved inside Moodle itself - the calendar stuff is great, you can use
RSS for school notices, or use the announcements forum, and we're on the way to
document managment, I don't know about e-mail though.