calendaring/phonebook server suggestions please.

[Steve Holdoway]

I've finally managed to get SWMBO converted to thunderbird ( well she
converted herself actually - Android opened her eyes! ), away from the
usual proprietary solution. So it now makes sense to extend the mail
server to provide more groupwarey options.

Does anyone have suggestions? I'm not looking for heavyweight solutions
like Zimbra, but servers that just work, simple to back up and
maintainable from the client software - *DAV based?

Cheers,

Steve