There has been some issues with installing the Cisco VPN Client in Ubuntu Karmak. Here is a Method how to install it.

Here is a list of articles that I setup for email hosting for a friend of mine. She hosts for a couple of different people. The first one is the one I used because it was for Debian and the system being used was Ubuntu, a Debian derivative. The second one is for gentoo. I included it for completeness and also using Courier. I'm not to happy with Courier, but it still works the same.

http://workaround.org/articles/ispmail-etch/

http://www.gentoo.org/doc/en/virt-mail-howto.xml