Yahoo Groups offer a free service (although you have to put up with advertising) for groups who wish to have their own web site and mailing list. You can restrict membership to those you invite and the site is password protected, so it is save from scammes and pishers.
I have developed a number information sheets that explain how to navigate the site, update profiles, et al. If you wish to start a group for your house, send me a note at morrison@unc.edu and I will forward you the materials that will help you get started.