evolution-data-server has an evil memleak somewhere in it's CalDAV-support for years now. (see http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=462664)

It's not even useable on my workstation with 2GiB of RAM, so I have to use it with Lightning (which is far away from good, too))

I don't think evolution-data-server is the right way.